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Biomedical subjects

M Salaspuro

Publications and source records attributed to M Salaspuro.

At least 73 records · Page 4Linked to original sources
PubMed1994

Carbohydrate-deficient transferrin during 3 weeks' heavy alcohol consumption.

To study the effect of controlled heavy drinking of 60 g ethanol/day for 3 weeks on carbohydrate-deficient transferrin (CDT), a commercial double antibody kit (CDTect) was used. By the end of the third drinking week, a statistically significant increase in the mean CDT level was observed. When compared to AST and gamma-glutamyltransferase, CDT was a more informative marker. However, only in 2 of the 10 volunteers did CDT exceed the upper normal level (20 units/liter) recommended by the manufacturer. This indicates that the sensitivity of CDT to detect heavy drinking is lower than that previously reported. The higher accuracy has in general been obtained in studies comparing healthy controls with a low alcohol consumption to alcoholics with an alcohol consumption higher than that used in the present experiment. Our results suggest that it remains to be established whether CDT, although better than AST and gamma-glutamyltransferase, will provide a clinically useful tool in identifying heavy drinkers in populations covering a wide range of alcohol consumption.

Adult↗
PubMed1994

Purification and characterization of Helicobacter pylori alcohol dehydrogenase.

Alcohol dehydrogenase of Helicobacter pylori (HPADH) was purified from the soluble fraction of cultured bacteria (strain NCTC 11637) by anion exchange and affinity chromatography. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the 160-fold purified enzyme displayed one protein band with a mobility that corresponded to an M(r) of 38,000. Although HPADH was capable of utilizing both NADP and NAD as cofactors in alcohol oxidation, it showed a strong preference for NADP over NAD. Kinetic studies revealed a Km value of 26 mM and a kcat value of 530 min-1 for ethanol/active site at 37 degrees C in 0.1 M potassium phosphate buffer (pH 7.4). The enzyme was considerably more active toward primary aliphatic alcohols than secondary alcohols. The Km and kcat values decreased as the chain length of the alcohol increased. Benzyl alcohol was a 100 times better substrate than ethanol in terms of kcat/Km values. At neutral pH, HPADH was more effective in aldehyde reduction than in alcohol oxidation. Because of its high specific activity for ethanol (14 units mg-1) under physiological conditions, HPADH can also effectively produce acetaldehyde at higher ethanol levels. This reversed function of HPADH and the production of toxic and reactive acetaldehyde could account for at least some of the gastrointestinal morbidity associated with H. pylori infection.

Acetaldehyde↗
PubMed1994

Helicobacter infection and gastric ethanol metabolism.

The organism frequently colonizing the stomach of patients suffering from chronic active gastritis and peptic ulcer disease--Helicobacter pylori--possesses marked alcohol dehydrogenase (ADH) activity. Consequently, Helicobacter infection may contribute to the capacity of the stomach to metabolize ethanol and lead to increased acetaldehyde production. To study this hypothesis, we first determined ADH activity in a variety of H. pylori strains originally isolated from human gastric mucosal biopsies. ADH activity was also measured in endoscopic gastric mucosal specimens obtained from H. pylori-positive and -negative patients. Furthermore, we used a mouse model of Helicobacter infection to determine whether infected animals exhibit more gastric ethanol metabolism than noninfected controls. Most of the 32 H. pylori strains studied possessed clear ADH activity and produced acetaldehyde. In humans, gastric ADH activity of corpus mucosa did not differ between H. pylori-positive and -negative subjects, whereas in antral biopsies ADH activity was significantly lower in infected patients. In mice, gastric ADH activity was similar or even lower in infected animals than in controls, depending on the duration of infection, despite the fact that the infectious agent used--Helicobacter felis--showed ADH activity in vitro. In accordance with this, Helicobacter infection tended to decrease rather than increase gastric ethanol metabolism in mice. In humans, it remains to be established whether the observed decrease in antral ADH activity associated with H. pylori infection can lead to reduced gastric first-pass metabolism of ethanol.

Acetaldehyde↗
PubMed1994

In vitro acetaldehyde formation by human colonic bacteria.

Incubation of human colonic contents with various ethanol concentrations (2.75-44 mM) in vitro at 37 degrees C resulted in significant accumulation of acetaldehyde--a toxic and highly reactive compound. At pH 9.6, all samples produced notable acetaldehyde concentrations (58 (13) microM; mean (SEM)) even from the lowest (2.75 mM) ethanol concentration, and the production of acetaldehyde increased lin-early with rising ethanol concentration (r = 0.97; p < 0.005), reaching a peak concentration of 238 (37) microM at 44 mM ethanol. The formation of acetaldehyde took place rapidly, as almost 50% of acetaldehyde formed during the total eight hour incubation was detectable after one hour, and 75% of the total after four hours. Maximal acetaldehyde production from 22 mM ethanol occurred at pH 9.6 (160 (35) microM) but appreciable concentrations were also seen at pH 7.4 (110 (38) microM) and pH 6.0 (63 (19) microM). At pH 4.0, by contrast, acetaldehyde formation was negligible (17 (5) microM). 4-Methylpyrazole, a potent inhibitor of alcohol dehydrogenase, showed a decreasing effect on acetaldehyde production in vitro but first at a concentration of 100 mM. Considerable acetaldehyde production by human colonic bacteria--if it occurs also in vivo--could constitute a risk factor for rectal cancer in heavy drinkers and also provide a pathogenetic mechanism for alcohol induced diarrhoea.

Acetaldehyde↗
PubMed1994

Effect of bismuth and nitecapone on acetaldehyde production by Helicobacter pylori.

BACKGROUND: We have recently shown that colloidal bismuth subcitrate inhibits cytosolic alcohol dehydrogenase of Helicobacter pylori as well as acetaldehyde production from excess ethanol. We now extend our studies to bismuth subsalicylate and nitecapone, a novel antiulcer agent. METHODS: Cytosol of H. pylori was incubated with 0.1% or 1% ethanol in the presence of different drug concentrations for 2 h, whereafter acetaldehyde formed was analyzed by head space gas chromatography. In addition, we incubated a culture solution containing intact bacteria with the drugs at 1% ethanol. RESULTS: Bismuth subsalicylate and nitecapone inhibit acetaldehyde formation from 0.1% ethanol by H. pylori cytosol at drug concentrations theoretically achievable in the stomach after intake of therapeutic doses of these drugs. Furthermore, colloidal bismuth subcitrate, bismuth subsalicylate, and nitecapone also inhibit acetaldehyde production by intact H. pylori, although rather high drug concentrations are required for this to occur. CONCLUSIONS: Inhibition of H. pylori acetaldehyde formation may be one of the mechanisms by which bismuth and nitecapone exert their effect in the treatment of H. pylori-related disorders.

Acetaldehyde↗
PubMed1994

Acetaldehyde and ethanol production by Helicobacter pylori.

By virtue of possessing alcohol dehydrogenase activity, cytosol prepared from Helicobacter pylori produces toxic acetaldehyde from ethanol in vitro. To approach the in vivo situation in the stomach, we have now investigation whether intact H. pylori--without addition of exogenous nicotinamide adenine dinucleotide--also forms acetaldehyde. Furthermore, to assess the energy metabolism of H. pylori, we determined whether the alcohol dehydrogenase-catalyzed reaction can run in the opposite direction with ethanol as the end-product and thereby yield energy for the organism. Intact H. pylori formed acetaldehyde already at low ethanol concentrations (at 0.5% ethanol, acetaldehyde, 64 +/- 21 and 75 +/- 9 mumol/l (mean +/- SEM) for strains NCTC 11637 and NCTC 11638, respectively). H. pylori produced ethanol in concentrations that can be significant for the energy metabolism of the organism. Acetaldehyde production by H. pylori may be an important factor in the pathogenesis of gastroduodenal diseases associated with the organism. The primary function of H. pylori alcohol dehydrogenase may, however, be alcoholic fermentation and consequent energy production under microaerobic conditions.

Acetaldehyde↗
PubMed1994

Mixed use of psychiatric drugs and alcohol by Finnish university students participating in a health screening.

OBJECTIVE: To obtain descriptive data on the mixed use of psychiatric drugs and alcohol. The difference and associations of health and mental risk factors between mixed users and others were also studied. DESIGN: A self-administered questionnaire as part of a general health screening. SETTING: First-year university students enrolled in the Finnish Student Health Service in Helsinki. Foreign students and those aged 30 years or over were excluded. SUBJECTS: 3,836 students were invited. The participation rate was 73.2% for the female and 53.2% for the male students. RESULTS: The mixed use of psychiatric drugs and alcohol with the aim of getting high, at least once, was reported by 3.6% of the female and 3.1% of the male students. However, only 1.0% had tried this mixed use more than once. Mixed users were more often smokers, heavy drinkers, or users of cannabis or heavy drugs. Male students tended to be mixed users because of anxiety, low self-esteem, and fears. Depression, stress, and sensation seeking were associated with mixed use in female students. CONCLUSIONS: Mixed use of psychiatric drugs and alcohol by young Finnish university students is still rare. There is a strong accumulation of other addictive behaviours among mixed users. Extra-personal reasons for mixed use were more prevalent among female students, and intra-personal reasons among male students.

Adult↗
PubMed1993

Characteristics of Helicobacter pylori alcohol dehydrogenase.

BACKGROUND: Helicobacter pylori shows alcohol dehydrogenase activity, which in the presence of ethanol leads to in vitro production of acetaldehyde, a toxic and highly reactive substance. The present study was undertaken to further define H. pylori-related ethanol and acetaldehyde metabolism by characterizing H. pylori alcohol dehydrogenase and by determining whether the organism possesses aldehyde dehydrogenase. METHODS: Cytosolic alcohol and aldehyde dehydrogenase activities were determined spectrophotometrically. Acetaldehyde produced by cytosol during incubation with ethanol was measured by head space gas chromatography. Isoenzyme pattern was studied using isoelectric focusing. RESULTS: Significant alcohol dehydrogenase activity was observed at a neutral pH known to occur in gastric mucus. The Km for ethanol oxidation was approximately 100 mmol/L for the two strains tested. Acetaldehyde was formed already from a low ethanol concentration known to prevail in the stomach endogenously. Isoelectric focusing of the enzyme showed activity bands with pI at 7.1-7.3, a pattern different from that of gastric mucosal alcohol dehydrogenase. 4-methylpyrazole inhibited enzyme activity in a competitive manner and suppressed the growth of the organism during culture. Neither Helicobacter strain studied showed aldehyde dehydrogenase activity and can thus not remove acetaldehyde by that pathway. CONCLUSIONS: Acetaldehyde production by H. pylori from exogenous or endogenous ethanol may be a pathogenetic mechanism behind mucosal injury associated with the organism.

Acetaldehyde↗
PubMed1993

Comparison of blood alcohol concentrations after beer and whiskey.

To determine whether blood alcohol concentrations achieved by ingestion of various alcoholic beverages differ as a function of prandial state, healthy male volunteers, aged 24 to 48 years, were given the same amount of alcohol (0.3 g/kg) as different beverages. The alcohol was consumed in three prandial states: postprandial (1 hr after a meal, n = 10), prandial (during the meal, n = 10), and preprandial (after an overnight fast, n = 9). Each subject was tested with both beer and whiskey, and in the postprandial state also with wine and sherry, in a within-subjects design. Blood alcohol concentrations were estimated by breath analysis for 4 hr or until concentrations reached zero. Peak blood alcohol levels were higher with beer than with whiskey in the postprandial and prandial conditions (p < 0.01), whereas the opposite was true in the preprandial state (p < 0.05). Similarly, the area under the blood alcohol curve was higher with beer in the prandial state (p < 0.05), and higher with whiskey in the preprandial condition (p < 0.01). Wine and sherry yielded peak concentrations intermediate between those of beer and whiskey in the postprandial state. The results indicate that a dilute alcoholic drink can yield either higher or lower blood alcohol levels than a concentrated beverage, depending on the prandial state.

Adult↗
PubMed1993

Screening for heavy drinking and alcohol-related problems in young university students: the CAGE, the Mm-MAST and the trauma score questionnaires.

The efficacy of the CAGE questions, the Malmö modification of the MAST questionnaire (Mm-MAST) and Skinner's five-item trauma score were used as a part of a larger health questionnaire in a sample of 1,663 female and 707 male first-year university students in Finland. The Mm-MAST correlated well (0.51-0.66) to reported alcohol intake and drinking for intoxication, the correlation (0.30-0.39) to CAGE was not as high but significant (p < .001). The trauma score did not correlate significantly to reported alcohol intake. Sensitivity and specificity for Mm-MAST > or = 3 in detecting heavy drinking, defined as a reported consumption of pure ethanol per year of at least 10 kg for women and at least 15 kg for men, was 63.8% and 87.1%, respectively, for female students and 86.3% and 87.4% for male students. Mm-MAST can be recommended as a useful screening tool for heavy drinking and alcohol-related problems in young university students. It is more specific and more sensitive than the CAGE questionnaire in this population. Skinner's trauma score was not useful for the screening of heavy drinking among young university students.

Adolescent↗
PubMed1993

Conventional laboratory tests as indicators of heavy drinking in young university students.

Conventional laboratory tests: gamma glutamyltransferase (GGT), alanine aminotransferase (ALAT), aspartate aminotransferase (ASAT), mean corpuscular volume (MCV), cholesterol, and high-density lipoprotein cholesterol (HDL-cholesterol) were studied as possible markers of heavy drinking in a sample of 1,619 first-year university students in Helsinki. Alcohol consumption was measured on a frequency-volume scale. No significant (p < 0.001) correlation between the laboratory tests and reported drinking was found. However, significant differences between different drinking groups were found in GGT, MCV, and HDL-cholesterol in both female and male students and in cholesterol in male students. We conclude that, even if alcohol drinking has some impact on GGT, MCV, HDL-cholesterol, and cholesterol (males), these tests are neither specific nor sensitive enough to be used as screening tests for heavy drinking in young students.

Adult↗
PubMed1993

Alcohol-use patterns in young university students in Finland.

OBJECTIVE: To obtain descriptive data on the alcohol-use patterns and the factors affecting them among Finnish first-year university students. DESIGN: Cross sectional survey with a self-administered questionnaire. SETTING: Finnish first-year university students. PARTICIPANTS: 3,836 students during the academic year 1989/90. The participation rate was 73.7% for female and 53.6% for male students. MAIN OUTCOME MEASURE: Frequency of drinking alcohol, heavy drinking, and drinking for intoxication, average alcohol consumption. RESULTS: The mean alcohol consumption for female students was 2.6 kg and for male students 6.5 kg of pure alcohol per year. 6.5% of the female students and 5.1 of the male students were abstainers. The heaviest drinking 10% consumed 42% of all consumed alcohol. 4.9% of the female students reported a consumption of at least 10 kg of pure alcohol per year and 11.7% of male students reported a consumption of at least 15 kg. The median for the frequency of drinking was every second week for the females and once a week for the males. Furthermore, drinking for intoxication was more frequent among the male than the female students. CONCLUSION: Male students have a higher alcohol consumption, drink more frequently, and are more often intoxicated than female students.

Adult↗
PubMed1993

Nutrient intake and nutritional status in alcoholics.

The modern techniques used in making reliable nutritional surveys and in assessing the nutritional status of alcoholic individuals have greatly improved our possibilities to determine the nutrient intake and to detect nutritional deficiencies in alcoholics from different social groups. In earlier studies, the rather high incidence of malnutrition in alcoholics can be related to the patients consisting of indigent, skid row alcoholics or patients with severe somatic complications. Later studies have revealed that nutritional deficiencies are rare among middle-class alcoholics without significant somatic complications. However, selective nutritional deficiencies may be found among lower-income and homeless alcoholic populations.

Alcohol Drinking↗
PubMed1992

Colloidal bismuth subcitrate and omeprazole inhibit alcohol dehydrogenase mediated acetaldehyde production by Helicobacter pylori.

We have recently shown that Helicobacter pylori possesses marked alcohol dehydrogenase (ADH) activity and is capable--when incubated with an ethanol containing solution in vitro--of producing large amounts of acetaldehyde. In the present study we report that some drugs commonly used for the eradication of H. pylori and for the treatment of gastroduodenal diseases are potent ADH inhibitors and, consequently, effectively prevent bacterial oxidation of ethanol to acetaldehyde. Colloidal bismuth subcitrate (CBS), already at a concentration of 0.01 mM, inhibited H. pylori ADH by 93% at 0.5 M ethanol and decreased oxidation of 22 mM ethanol to acetaldehyde to 82% of control. At concentrations above 5 mM, CBS almost totally inhibited acetaldehyde formation. Omeprazole, a drug also known to suppress growth of H. pylori, also inhibited H. pylori ADH and suppressed bacterial acetaldehyde formation significantly to 69% of control at a drug concentration of 0.1 mM. By contrast, the H2-receptor antagonists ranitidine and famotidine showed only modest effect on bacterial ADH and acetaldehyde production. We suggest that inhibition of bacterial ADH and a consequent suppression of acetaldehyde production from endogenous or exogenous ethanol may be a novel mechanism by which CBS and omeprazole exert their effect both on the growth of H. pylori as well as on H. pylori associated gastric injury.

Acetaldehyde↗
PubMed1992

Alcohol dehydrogenase mediated acetaldehyde production by Helicobacter pylori--a possible mechanism behind gastric injury.

Two standard Helicobacter pylori strains showed significant cytosolic alcohol dehydrogenase activity and produced considerable amounts of acetaldehyde when incubated with an ethanol containing solution in vitro. The alcohol dehydrogenase activity of the Helicobacter pylori strains was almost as high as that found in Klebsiella pneumoniae and far greater than that in Escherichia coli or Campylobacter jejuni. The amount of acetaldehyde produced by cytosol prepared from Helicobacter pylori exceeded that by any of the other bacteria studied. The bacterial production of acetaldehyde--a highly toxic and reactive substance--could be an important factor in the pathogenesis of Helicobacter pylori associated gastric injury and increased risk of gastric cancer.

Acetaldehyde↗
PubMed1992

Alcohol and sauna bathing: effects on cardiac rhythm, blood pressure, and serum electrolyte and cortisol concentrations.

The effect of heavy drinking and sauna bathing on cardiac rhythm, blood pressure, and serum electrolyte and cortisol concentrations was studied in 10 healthy male volunteers. Sauna bathing induced a comparable, significant increase in heart rate with and without alcohol consumption. During sauna bathing without alcohol, systolic blood pressure remained at the baseline level, whereas sauna and alcohol together decreased systolic blood pressure markedly from 136 +/- 4 to 113 +/- 3 mmHg (P less than 0.01). Neither sauna alone, nor sauna combined with alcohol intake, increased the frequency of premature ventricular complexes. Serum potassium, calcium and cortisol concentrations changed slightly during sauna, but alcohol consumption did not contribute further to this. In conclusion, sauna bathing, even in combination with heavy drinking, does not appear to provoke cardiac arrhythmias in healthy young men. However, the risk of hypotension is increased when sauna bathing is combined with alcohol consumption.

Adult↗