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T Koivula

Publications and source records attributed to T Koivula.

At least 109 records · Page 6Linked to original sources
PubMed1991

Nucleotide sequence of the secY gene from Lactococcus lactis and identification of conserved regions by comparison of four SecY proteins.

Sec Y is an integral membrane protein which participates in the translocation of proteins through the bacterial cell membrane. We have cloned the sec Y gene of Lactococcus lactis, and found its deduced protein sequence, 439 amino acids long, to be similar in length to the previously determined Sec Y proteins of Escherichia coli, Bacillus subtilis and Mycoplasma capricolum. Comparison of the L. lactis Sec Y to the 3 other Sec Y proteins revealed 90 conserved amino acid residues (21%). Nearly half of the conserved residues are clustered in 2 of the 10 transmembrane segments, and in 2 of the 6 cytoplasmic regions. Some of the conserved regions are apparently responsible for the interactions of Sec Y with signal sequences, and the proteins SecE and SecA.

Amino Acid Sequence↗
PubMed1991

Improved prognostic impact of S-phase values from paraffin-embedded breast and prostate carcinomas after correcting for nuclear slicing.

Nuclear debris may significantly interfere with the analysis of S-phase fraction (SPF) from paraffin-embedded tumors. We used a background subtraction algorithm to compensate for the effects of slicing of tumor cell nuclei during preparation of paraffin-embedded specimens. DNA histograms were analyzed from 88 node-negative breast and from 78 prostatic carcinomas. Median SPFs corrected for nuclear slicing were lower than uncorrected ones in both breast cancer (7.6% vs. 5.7%) and prostate cancer (6.7% vs. 4.2%). The median SPF value in each group was used as a cut-off point in survival studies. As compared with the uncorrected SPFs, corrected SPF levels resulted in a more significant survival difference between breast cancer patients with above and below median SPF (p = 0.0014 vs. p = 0.014) and in a higher relative risk (RR) of death (4.5 vs. 3.1). The same was true for prostate cancer survival (p less than 0.0001 vs. p = 0.002) and RR (5.3 vs. 3.1). Compared with the exponential background subtraction method, the sliced nuclei correction was more reproducible and could be applied in all evaluable histograms without the risk of overcompensation. In conclusion, our results support the use of background correction with the sliced nuclei model in DNA flow cytometric studies of archival tissues.

Breast Neoplasms↗
PubMed1991

Association of a haemoglobin-acetaldehyde adduct with questionnaire results on heavy drinkers.

A new biological alcohol marker, the ratio between the acetaldehyde-induced haemoglobin fraction HbA1ach and the glycated haemoglobin fraction HbA1c (HbA1ach/HbA1c), was studied in association with data obtained in a questionnaire, the Malmö modified Michigan alcoholism screening test (Mm-MAST), completed by 270 consecutive middle-aged men participating in a voluntary health screening. None of them had earlier alcoholic health or alcohol-dependent social problems. The nine-question Mm-MAST correlated positively with the ratio of HbA1ach/HbA1c (r = 0.272, P less than 0.001). In the three drinker groups defined according to the questionnaire, HbA1ach/HbA1c values were significantly higher among heavy drinkers (mean = 40, S.E.M. = 1) than among teetotallers (mean = 32, S.E.M. = 2, P less than 0.01) or social drinkers (mean = 35, S.E.M. = 1, P less than 0.01). In the groups formed according to the respondents' own alcohol anamnesis there was no significant difference between the marker values, but the Mm-MAST score was significantly higher in both social (P less than 0.001) and heavy drinkers' (P less than 0.001) groups as compared with teetotallers. This shows that the questionnaire detected heavy drinkers better than the self-given anamnesis. The correlation of HbA1ach/HbA1c and the questionnaire means that the biological marker studied represents a new possibility to identify heavy drinkers before alcoholic health problems or social consequences have appeared.

Acetaldehyde↗
PubMed1991

Nucleotide sequence of a Lactococcus lactis gene cluster encoding adenylate kinase, initiation factor 1 and ribosomal proteins.

We have previously isolated a putative promoter from the Lactococcus lactis subsp. lactis chromosome. We now report the sequence of the promoter fragment and its extension in the 5'-direction. The region contains several open-reading frames which correspond to ribosomal protein L15, SecY, adenylate kinase, initiation factor 1 and ribosomal proteins B and S13. The order of the genes, rplO (L15), secY, adk, infA, rpmJ (B) and rpsM (S13), is similar to that in the spc and alpha operon region of Bacillus subtilis, with the exception of the map gene, coding for methionine amino peptidase, which is located between adk and infA in B. subtilis. The putative promoter is located between adk and infA.

Adenylate Kinase↗
PubMed1991

Isolation and characterization of Lactococcus lactis subsp. lactis promoters.

DNA fragments with promoter activity were isolated from the chromosome of Lactococcus lactis subsp. lactis. For the isolation, a promoter probe vector based on the cat gene was constructed, which allowed direct selection with chloramphenicol in Bacillus subtilis and L. lactis. Four of the putative promoters (P1, P2, P10, and P21) were analyzed further by sequencing, mapping of the 5' end of the mRNA, Northern (RNA blot) hybridization, and chloramphenicol acetyltransferase activity measurements. From these fragments, -10 and -35 regions resembling the consensus Escherichia coli sigma 70 and B. subtilis sigma 43 promoters were identified. Another set of promoters, together with a signal sequence, were also isolated from the same organism. These fragments promoted secretion of TEM beta-lactamase from L. lactis. When the two sets of promoters were compared, it was found that the ones isolated with the cat vector were more efficient (produced more mRNA). By changing the promoter part of the promoter-signal sequence fragment giving the best TEM beta-lactamase secretion into a more efficient one (P2), a 10-fold increase in enzyme production was obtained.

Base Sequence↗
PubMed1991

Secretion of TEM beta-lactamase with signal sequences isolated from the chromosome of Lactococcus lactis subsp. lactis.

With TEM beta-lactamase as a reporter gene, a set of expression-secretion-promoting fragments were isolated from the chromosome of Lactococcus lactis subsp. lactis. The fact that only translocated beta-lactamase renders cells resistant to ampicillin allowed direct ampicillin selection with an Escherichia coli vector (pKTH33). The clones showing the greatest ampicillin resistance were subcloned onto a replicon capable of replication in lactic acid bacteria (pVS2), and the nucleotide sequences of the relevant fragments were determined. The structure of the secretion-promoting fragments in general resembled that of gram-positive true signal sequences, with a strongly positively charged N terminus, a long hydrophobic core, and a putative signal peptidase recognition site. The promoterlike sequences preceding the signal sequences matched well with those of previously published lactococcal promoters. In addition to E. coli, the functioning of these expression-secretion cassettes was studied in three gram-positive hosts: Bacillus subtilis, L. lactis, and Lactobacillus plantarum. Efficient expression and secretion of TEM beta-lactamase into the culture medium of each gram-positive host was obtained. Furthermore, when a strain of L. lactis subsp. lactis showing increased sensitivity to lysozyme was compared with a standard laboratory strain, threefold-higher secreted enzyme activities were detected.

Amino Acid Sequence↗
PubMed1991

Postprandial blood concentrations of insulin-independent carbohydrate, galactose, in oral test after gastric surgery.

In order to examine the postprandial blood concentrations of insulin-independent carbohydrates after gastric surgery oral galactose test (1.65 g/kg body weight in water, 33%, w/v) was performed in 55 symptomatic patients and in 5 healthy subjects. There were patients after total gastrectomy (TG) (n = 17), gastric resection with (GRS, n = 17) or without (GR; n = 12) selective vagotomy, and after proximal selective vagotomy (PSV, n = 9). The patients had immediately after drinking the test solution a 2- to 5-fold higher blood galactose concentration than the healthy subjects. The TG patients had the most rapid, the healthy subjects the slowest and the GR and GRS patients an intermediate rapid, immediate increase of blood galactose concentration. The TG patients showed a plateau 40-60 min and a decrease 60-90 min after the start of the test. The PSV patients showed a plateau 60-90 min after the commencement of the test. The GR and GRS patients and the healthy subjects had a continuous increase in blood galactose concentration during the whole test period, but the maximal point 90 min after the drinking of the solution was lower in the GRS than in the GR patients and lowest in the healthy subjects. The PSV patients had a lower blood galactose curve than the TG, GRS and GR patients but higher than the healthy subjects except the plateau 60-90 min postprandially.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbohydrate Metabolism↗
PubMed1991

Increased beta-lactoglobulin absorption during rotavirus enteritis in infants: relationship to sugar permeability.

We studied absorption of the potentially allergenic protein beta-lactoglobulin during acute rotavirus diarrhea in infants and assessed the relationship of this macromolecular absorption with intestinal sugar permeability. After oral rehydration, 38 patients with acute gastroenteritis were given orally a 100-ml solution containing 4 g (11.7 mmol/L) of lactulose and 0.8 g (4.4 mmol/L) of mannitol, and their recovery rate as shown in urine passed during the subsequent 5 h was measured. A blood sample was taken 2 h after a milk feed for ELISA measurement of beta-lactoglobulin in circulating immune complexes. Twelve nondiarrhea patients were studied after an overnight fast as controls. Immune complexes containing beta-lactoglobulin were found in the serum of all, but the levels [median (range)] were significantly higher in patients with rotavirus diarrhea [686 (36-4352)] than in nondiarrhea patients [165 (0-2594)]; p = 0.007. The mean (95% confidence interval) lactulose/mannitol urinary recovery ratios were increased in patients with acute diarrhea [0.19 (0.10, 0.30)] compared to nondiarrhea patients [0.01 (0.005, 0.02)]; p = 0.0001. Thus, a significant correlation between beta-lactoglobulin absorption and sugar permeability was found; Spearman's rank correlation coefficient = 0.42, p = 0.004. This correlation was not, however, direct but was due to an inverse relationship between urinary recovery of mannitol and serum beta-lactoglobulin immune complexes. These results indicate that rotavirus gastroenteritis is associated with enhanced beta-lactoglobulin absorption and elevated lactulose/mannitol permeability test results, but these represent different phenomena.

Antigen-Antibody Complex↗
PubMed1991

Nephrotoxicity of tobramycin. Value of examining various protein and enzyme markers.

The value of various protein and enzyme markers for the assessment of early nephrotoxicity of tobramycin was studied in 18 patients with febrile infection. The renal clearance of creatinine and the excretion of the following protein and enzyme markers were measured on the first and the last day of the 5-8 day treatment period: albumin, N-acetyl-beta-D-glucosaminidase (NAG), beta 2-microglobulin, alpha-amylase, lysozyme and retinol-binding protein (RBP). Diurnal excretions of beta 2-microglobulin, lysozyme and RBP, all markers of tubular dysfunction, were already increased on the first treatment day, compared to similar control patients treated with non-aminoglycoside antibiotics and reference values of our laboratory. The excretion of NAG, an enzyme released from tubular cell lysosomes, was not increased initially, but on the last treatment day it was increased most consistently of all the markers studied. Glomerular filtration rate was halved in 5 of the patients. The results suggest that the initial increase in beta 2-microglobulin, lysozyme and RBP excretion is a result of an early tubular transfer block by tobramycin, whereas the late increase in NAG excretion probably reflects the progress of tubular cell damage during the course of aminoglycoside therapy.

Acetylglucosaminidase↗
PubMed1991

A human Lactobacillus strain (Lactobacillus casei sp strain GG) promotes recovery from acute diarrhea in children.

To determine the effect of a human Lactobacillus strain (Lactobacillus casei sp strain GG, Gefilac) on recovery from acute diarrhea (82% rotavirus), 71 well-nourished children between 4 and 45 months of age were studied. After oral rehydration, the patients randomly received either Lactobacillus GG-fermented milk product, 125 g (10(10-11) colony-forming units) twice daily (group 1); Lactobacillus GG freeze-dried powder, one dose (10(10-11) colony-forming units) twice daily (group 2); or a placebo, a pasteurized yogurt (group 3) 125 g twice daily; each diet was given for 5 days, in addition to normal full diet otherwise free of fermented dairy products. The mean (SD) duration of diarrhea after commencing the therapy was significantly shorter in group 1 (1.4 [0.8] days) and in group 2 (1.4 [0.8] days) than in group 3 (2.4 [1.1] days); F = 8.70, P less than 0.001. After rehydration, each dietary group maintained a positive weight trend. The urinary lactulose-mannitol recovery ratios (means [95% confidence intervals]) on admission were 0.09 (0.03, 0.24) in group 1, 0.12 (0.07, 0.22) in group 2, and 0.08 (0.04, 0.18) in group 3; no significant alterations in intestinal permeability were observed at retesting after 2 days of realimentation. The result indicates that early nutritional repletion after rehydration causes no mucosal disruption and is beneficial for recovery from diarrhea. It is further suggested that Lactobacillus GG in the form of fermented milk or freeze-dried powder is effective in shortening the course of acute diarrhea.

Acute Disease↗
PubMed1990

Inter-laboratory comparison of DNA flow cytometric results from paraffin-embedded breast carcinomas.

Consecutive sections from 33 paraffin-embedded human breast carcinomas without intratumor heterogeneity were sent for flow cytometric (FCM) DNA analysis in two experienced laboratories. FCM instruments, run conditions, and tumor disaggregation procedures were different in the two laboratories. In four cases (12%) the laboratories reported a different DNA ploidy and DNA index (DI). These variations were due to analytical reasons, differences in the detection rates of near-diploid and tetraploid DIs, not due to interpretation of data or the criteria used for aneuploidy. There was a significant correlation between S-phase fractions (SPF) obtained in the two laboratories (r = 0.90, p less than 0.0001) if only cases with concordant DI were included. Discordant DI usually led to very different SPF values.

Aneuploidy↗
PubMed1990

Discordant results between radioligand and immunohistochemical assays for steroid receptors in breast carcinoma.

Surgical biopsy specimens of 179 breast carcinoma were studied by steroid-binding and immunohistochemical assays or oestrogen and progesterone receptors (ER, PR) in order to explore reasons for discordant results between the two assay types. Receptor statuses in 18% of ER assays and 30% of PR assays were in disagreement. Immunohistochemistry-positive steroid-binding-negative status predominated among the discordant ER assays, while the discordant PR assays displayed the opposite situation. In discordant assays receptor concentration was significantly more often close to the cut-off (10-50 fmol mg-1) than in the concordant ones. Low binding affinity (high Kd) was also significantly associated with disagreeing assay results. These observations clearly indicate that immunohistochemical ER and PR assays measure high-affinity binding components (i.e. type I receptors) in steroid-binding assays. ER but not PR assays in premenopausal women disagreed more often than those in post-menopausal women. Such factors as histological type, specimen size in steroid-binding assay, grade of malignancy and tumour necrosis were statistically unrelated to agreement or disagreement of receptor assays.

Adult↗
PubMed1990

The efficiency of a questionnaire in detecting heavy drinkers.

The suitability of the nine-question Malmö modified Michigan Alcoholism Screening Test (Mm-MAST) was tested on 133 40-year-old men and 140 45-year-old men attending a voluntary population health screening in a typically week-end-drinking society. With a cut-off level of two 'yes' answers 29% of the middle-aged male population has been reported to give a positive result in this questionnaire. In our study alcoholics were excluded. The amount and type of alcohol consumed per week was asked. The subjects were divided into three groups: (1) social drinkers (0 or 1 'yes' answer), (2) suspect abusers (two 'yes' answers), and (3) abusers (three or more 'yes' answers or drinking at least 280 g absolute alcohol per week). Group 2 reported drinking more than group 1, but according to biological markers they belonged better to group 1 than group 3. With the originally recommended cut-off level of two 'yes' answers 50.8% of 40-year-old men and 36.5% of 45-year-old men in our study proved positive. With the three 'yes' answer criterion the corresponding percentages were 28.5 and 24.0. Forty- and 45-year-old men in group 2 gave many positive answers in the question concerning week-end drinking and avoidance of alcohol for a time, as did 40-year-old men in the question concerning bad conscience after drinking. Beer and spirits were the most popular beverage combination and week-end drinking was the commonest drinking habit. The number of positive answers correlated well with the announced amount of alcohol.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Detection of a new acetaldehyde-induced hemoglobin fraction HbA1ach by cation exchange liquid chromatography.

We developed a sensitive cation exchange liquid chromatographic method for analysis of acetaldehyde binding with hemoglobin. When human hemolysates were incubated in vitro with micromolar concentrations of acetaldehyde without reducing agents, HbA0 was found to form two new fractions. One of them was eluated with HbA1c, whereas a novel, previously undescribed fraction was detected between HbF and HbA1c. This new fraction was termed HbA1ach. The mean within-assay variation for the different hemoglobin fractions varied from 0.45 (HbA0) to 8.2% (HbA1ach) and the between-assay variation from 0.6 to 19.3%, respectively. After incubation with [1,2(14)C]acetaldehyde the specific radioactivity of HbA1ach was about 10 times higher than that of HbA0 and twice as high as the activity of the HbA1c fraction. The reaction kinetics of the formation of hemoglobin adducts were studied in vitro by incubation of hemolysates with various acetaldehyde concentrations. Acetaldehyde caused both short-term and permanent changes in hemoglobin. Even low acetaldehyde concentrations from 10 to 100 mumol/liter caused detectable changes in hemoglobin. During incubation the amount of HbA1ach and HbA1c fractions increased rapidly within the first 10 min and decreased slowly during the next hr but did not return to the initial levels. This suggests that only the part of binding of acetaldehyde with hemoglobin is irreversible and the changes can be already detected after incubation with physiological acetaldehyde concentrations.

Acetaldehyde↗
PubMed1990

High density lipoprotein cholesterol and triglycerides as markers of angiographically assessed coronary artery disease.

Serum triglycerides, high density lipoprotein (HDL) cholesterol, and total cholesterol were measured in 698 patients examined by angiography. The ratio of HDL cholesterol to total cholesterol was significantly lower in patients with single, double, and triple vessel disease than in patients without disease. The serum concentration of triglyceride was significantly higher in patients with single, double, and triple vessel disease than in those without coronary artery disease. Similar proportion of patients with coronary artery disease and without had serum cholesterol concentrations of greater than or equal to 6.5 mmol/l, but total cholesterol was significantly higher in patients with single, double, and triple vessel disease than in those without. HDL cholesterol (less than 1.0 mmol/l), triglycerides (greater than 2.0 mmol/l), and the ratio of HDL cholesterol to total cholesterol (less than 0.20) were significantly better than total cholesterol as indicators of coronary risk.

Adult↗
PubMed1990

Basic urinalysis and urine culture: Finnish recommendations from the working group on clean midstream specimens.

A recommendation for basic urinalysis and urine culture is published as an attempt to improve the clinical value of urinary tests and to create a system that utilizes laboratory work as sensibly as possible. More clinical background information is needed when basic urinalysis and urine culture is performed in stages. Collection and storage of urine specimens are standardized in addition to used equipment and bacterial culture. Cytological supravital stain improves qualitative and quantitative findings of urine sediment cytology. A close cooperation between central hospital district is necessary and stressed for further bacterial cultures in more complicated microbiological findings.

Adult↗