Comparison between a swim-up and a Percoll gradient technique for the separation of human spermatozoa

Two methods of separating human sperm were compared using twenty-two semen samples. The sperm were separated by a swim-up technique or by self-migration on a Percoll gradient followed by medium change. After separation, the sperm obtained were assessed for progressive motility, ATP content, energy charge index ([ATP + 0.5 ADP]/[ATP + ADP + AMP]) and morphology. In general, and especially for semen samples containing less than 20 X 10(6) sperm/ml, separation by Percoll gradient selected sperm that were superior to those separated by the swim-up technique. The relatively high energy charge index (greater than 0.8) showed that the sperm tolerated the separation conditions well. It is suggested that self-migration on a Percoll gradient should prove useful for obtaining sperm of high quality.     

Hospital versus population controls in a retrospective study on diet and stomach cancer

The aim of the present study is to evaluate drawbacks and advantagesof the choice of hospital versus population controls in a casecontrol study on diet and cancer through the analysis of a retrospectivestudy on diet and gastric cancer (GC) conducted in Forli, Italy,involving 232 cases, 430 population controls and 252 hospitalizedcontrols. The present paper reports the comparison of resultson diet and GC risk obtained using the 2 types of controls.Population controls tended, in general, to eat all kinds offoods slightly more frequently (bread, pasta, cold cuts, freshfish, seasoned cheeses, legumes, garlic, onions and preservedfruits), with the exception of cooked vegetables, which werereported less frequently by population than by hospital controls.ORs for specific foods adjusted for confounders and other foodswere consistent in the separate models including populationand hospital controls respectively for all food groups, withthe exception of cooked vegetables which represented a protectivefactor only when hospital controls were considered (high consumers,population controls: adjusted, OR=0.9, trend p value 0.54; highconsumers, hospital controls, adjusted OR=0.5, trend p value<0.01). Hospital controls were slightly less often currentsmokers (22.6 versus 30.0%) and more often regular wine drinkers(57.5 versus 47.8%) compared with population controls, but noneof these variables was associated with GC risk. The main resultsin this study were consistent using both types of controls,nevertheless the distribution of some dietary variables notrelated to the disease under study differed between the 2 controlgroups, suggesting some caution in the use of hospital controlswhen studying diseases other than GC.     

Essential Nature of Choline with Implications for Total Parenteral Nutrition

Choline is known to be important in many metabolic pathways; at this time, however, it is not considered an essential nutrient for human beings. Current evidence strongly suggests that choline is “conditionally essential,” particularly for patients receiving total parenteral nutrition (TPN). Studies in patients receiving long-term TPN have shown that low levels of plasma choline are common and can be associated with hepatic steatosis. Treatment of these patients with oral administration of choline improved plasma levels and decreased hepatic fat content; however, oral choline supplements are associated with poor compliance. More recently, investigators have evaluated intravenous administration of choline as a treatment for TPN-associated hepatic steatosis in patients with documented subnormal plasma free-choline levels. Initial results indicate that intravenous administration of choline may be an effective treatment for TPN-associated hepatic dysfunction.     

A STUDY ON THE POSTJUNCTIONAL EXCITATORY α-ADRENORECEPTOR SUBTYPES IN THE MESENTERIC ARTERIAL BED OF THE RAT

• 1 The nature of the postsynaptic adrenoreceptor subtypes which mediate vasoconstriction in the mesenteric arterial bed of the rat was investigated using mixed and selective α₁, α₂ and β-agonists and antagonists.
• 2 Phenylephrine (PE) an α₁selective agonist and noradrenaline (NA) a mixed α₁and α₂-agonist, produced a rise in perfusion pressure (vasoconstriction). The responses to NA remained stable with time whereas responses to PE considerably increased.
• 3 UK14304 an α₂-selective agonist at low doses (10^?8 ?10^?7 moles), caused small, slow contractions in most preparations. Repeated administration of these doses or slightly higher ones, desensitized the tissue to this compound but not to NA or PE. Finally, UK14304 given simultaneously with NA or PE, at doses higher than 5 × 10^?7 moles, reduced contractions to the latter compounds and this effect was not altered by 10^?7 M rauwolscine, an α₂-selective antagonist.
• 4 Prazosin, an α₁-selective antagonist, as expected, reduced contractions to NA considerably at 10^?10 ?10^?8 M and abolished contractions to UK14304 at 2 × 10^?9 M.
• 5 Rauwolscine, at 10^?8 M, potentiated contractions to NA and at 10^?6 M reduced contractions to both NA and PE (when compared to time controls).
• 6 When propranolol (10^?6 M), a β-antagonist was included in the perfusion fluid, rauwolscine no longer potentiated responses to NA but reduced them at all concentrations. Under the same conditions rauwolscine affected the responses to PE in a similar direction to that observed in the absence of propranolol.
• 7 These results suggest that in the rat mesenteric arterial bed:

• a. rauwolscine exerts an effect additional to α₂-adrenoreceptor antagonism. Modification of this effect by propranolol indicates an interaction between this effect of rauwolscine and the β-adrenoreceptor.
• b. vasoconstriction in the mesenteric arterial bed of the rat is mainly mediated postsynaptically by α₁-adrenoreceptors although the contribution of an α₂-mediated component cannot be excluded.
• c. UK14304 is an α₁-partial agonist as well as an α₂-agonist.

     

ANTIBODIES MADE AGAINST A FORMALDEHYDE-PROTEIN ADDUCT CROSS REACT WITH AN ACETALDEHYDE-PROTEIN ADDUCT. IMPLICATIONS FOR THE ORIGIN OF ANTIBODIES IN HUMAN SERUM WHICH RECOGNIZE ACETALDEHYDE-PROTEIN ADDUCTS

Acetaldehyde, the major metabolite of ethanol, reacts with lysineand other free amino groups on proteins to form acetaldehyde-proteinadducts. The presence of antibodies which recognize such acetaldehyde-proteinadducts in sera from alcoholics has been attributed to an immuneresponse to such adducts. Complicating this conclusion is thefinding that sera from non-alcoholic control subjects also containantibodies which recognize acetaldehyde-protein adducts. Inthe current research we sought to determine whether antibodieswhich recognize epitopes formed by the reaction of a proteinwith acetaldehyde can be formed in response to a protein modifiedwith a structurally related protein adduct. We modified lysineresidues on apolipoprotein (apo) B-100 with acetaldehyde andformaldehyde under reducing conditions, to form -N-methyl-and-N-ethyl-lysine residues, and with acetic anhydride to form-N-acetyl-lysine residues, and made antibodies against thesemodified proteins in guinea-pigs. In ELISA assays antibodiesmade against methylated apoB-100 (Me-apoB) cross-reacted effectivelywith ethylated apoB-100 (Et-apoB), while antibodies made againstacetic anhydride-modified apoB-100 did not cross-react. We concludethat methyl-lysine shares one or more immunoreactive epitopeswith ethyl-lysine, and that antibodies which recognize acetaldehyde-modifiedproteins can be formed in response to formaldehyde-modifiedproteins. We demonstrate that sera from both alcoholics andnon-drinkers contain antibodies which recognize Me-apoB andEt-apoB and that the titres of these antibodies are comparable.These data raise the possibility that some human serum antibodieswhich recognize acetaldehyde-modified protein epitopes may havebeen made against formaldehyde-modified protein epitopes. Thesedata also illustrate the difficulty in assigning a unique causalrelationship between the presence of an antibody, and the immunogenresponsible for the formation of such antibody.     

Using socio-economic differences in knowledge and attitudes to shape community alcohol programmes: experiences from the Kirseberg Project

Community-based public health projects have become increasinglyimportant as a tool for health promotion. This approach hasbeen considered appropriate also in addressing socio-economicdifferences in health, although little is known about socio-economicdifferences in perception of health as a community issue. Ouraim was to study socio-economic differences in awareness andknowledge about the Kirseberg Project and in attitudes towardsthe concept of health as a local community issue. The KirsebergProject was initiated in 1988. The primary prevention aims areto reduce alcohol consumption in the population in order todecrease the incidence of alcohol-related problems. Kirsebergis an area with 10000 inhabitants in the north-eastern partof the city of Malmö (population 230000), Sweden. A sampleof 400 people in the area between the ages of 20 and 75 yearsof age was randomised from the population register and interviewedby telephone. Of the sample, 73.3% responded. Of the respondents,65.2% were aware of the project and 38.6% had knowledge aboutit. Socio-economic differences were found both regarding knowledgeand attitudes. Individuals in the high socio-economic status(SES)-group were better informed about the project than thelow SES-group, more often associated the project with the promotionof the community spirit, tended to give more positive answersto the questions about important local health issues, demonstratedhigher adherence to the social environment issues and were moreinterested in local health promotion activities. Our conclusionis that the socio-economic knowledge differences which werefound in the Kirseberg Project should be seen as shortcomingsin the health educational campaign rather than as a first stepin a determined social process. The issue of how the explicitnotions and the hidden agenda of a health promotion campaigncorrespond with central attitudes and values in different populationgroups in the target community must be carefully investigated.     

Sleep-related sweating in obstructive sleep apnoea: association with sleep stages and blood pressure

The aim of this study was to investigate sleep-related sweating as a symptom of obstructive sleep apnoea (OSA). Fifteen otherwise healthy male non-smoking patients with untreated moderate-to-severe OSA underwent polysomnography, including measurements of skin and core body temperature and electrodermal activity (EDA) as an objective indicator of sweating. Evening and morning blood pressure was measured as well as catecholamines in nocturnal urine. All measurements were repeated after 3 months on successful continuous positive airway pressure (CPAP) treatment. The untreated OSA subjects had a mean (±SD) apnoea–hypopnoea index of 45.3 ± 3.9 and a mean EDA index during sleep of 131.9 ± 22.4 events per hour. Patients with higher EDA indices had higher systolic blood pressure in the evening and morning ( P  = 0.001 and 0.006) and lower rapid eye movement (REM) sleep percentage ( P  = 0.003). The EDA index decreased significantly to 78.5 ± 17.7 in the patients on CPAP treatment ( P  = 0.04). The decrease correlated with lower evening systolic and diastolic blood pressure ( P  = 0.05 and 0.006) and an increase in REM% ( P  = 0.02). No relationship was observed between EDA and skin or core body temperature, or to catecholamine levels in urine. OSA patients who experience sleep-related sweating may have increased blood pressure and decreased REM sleep compared with other OSA patients. CPAP treatment appears to lower blood pressure and increase REM sleep to a higher extent in these patients compared with other OSA patients.     

Accuracy at radiography and probing for the diagnosis of proximal caries

In 63 teenagers the proximal surfaces of premolars to be extracted for orthodontic reasons and the adjacent surfaces of neighboring teeth, 598 surfaces in all, were examined radiographically and by probing. Direct inspection after extraction revealed that 51% of the surfaces had incipient carious lesions and 5% lesions with cavities. Of the surfaces with cavities 82.1% were correctly diagnosed radiographically if any radiolucency, regardless of its extent, was used as a diagnostic criterion. However, this yielded a false positive rate of 19.6%. If only radioluccncies extending at least into the inner third of the enamel were called positive the true positive rate was 36.7% and the associated false positive rate 1.6%. At a 5% cavity frequency the predictive positive values were 17% and 53%, respectively. Probing yielded a true positive rate of about 29% and a false positive rate of 1.1% with a predictive positive value of 50-57%. All radiolucencies extending into the dentin were associated with cavities. When the most liberal radiographic criterion was used 37.5% of all carious lesions, whether associated with a cavity or not, were detected and 3.8% of sound surfaces were falsely called carious. The corresponding predictive positive value at the actual rate of incipient lesions and lesions with cavities was 92.6%.     

THE SIGNIFICANCE OF DISTURBANCES OF THE MOTOR SYSTEM OF THE EYE IN LOW VISION CHILDREN

Defects of the neuromotor system of the eye found to occur in 80% of 70 visually impaired children. The influence of such defects on the developing visual acuity is discussed. Early and intensified treatment is suggested to minimize negative effects and promote visual development.