Differences in molecular epidemiology of Staphylococcus aureus and Escherichia coli in nursing home residents and people in unassisted living situations.

BACKGROUND: The usefulness of colonization pressure as a working model and proxy for infection transmission is limited due to the inability to grade or quantify the specific risk within environments that are subject to change. AIM: To elaborate on the colonization pressure model by comparing the molecular epidemiology of two bacteria, Staphylococcus aureus and Escherichia coli, among residents in a nursing home and people in unassisted living situations. METHODS: A cross-sectional study of 73 elderly residents from a village in south-central Sweden was conducted. Of these, 35 were residents of a nursing home, and 34 lived in an own place of residence in the same geographical area. Samples of two representative bacterial species were collected from multiple body sites and analysed for molecular diversity. FINDINGS: Combining all body sites, 47% of the participants were colonized with S. aureus and 93% with E. coli. The nursing home group, the group in unassisted living situations, and both units combined, held 16, 17, and 29 different S. aureus spa types, respectively. The corresponding numbers of different E. coli serogenotypes were 34, 28, and 48. Diabetes mellitus was associated with more frequent colonization with S. aureus. CONCLUSION: The molecular diversity of bacteria found within different forms of accommodation was within the same range. Hospital quality hygiene might have contributed to the absence of homogenization of the molecular diversity within the nursing home group. Diabetes mellitus might have played a role in a patient selection characterized by advanced age.

Plasma concentrations of alpha-1-acid glycoprotein in preterm and term newborns: influence of mode of delivery and implications for plasma protein binding of local anaesthetics.

BACKGROUND: Alpha-1-acid glycoprotein (AAGP) is an acute-phase protein with high affinity for amide local anaesthetics (LAs), and a major determinant of free and potentially toxic concentrations of LAs in plasma. Neonates are known to have lower plasma concentrations of AAGP than adults, and are at risk of developing high free concentrations of LAs. Data regarding AAGP in newborns are so far sparse. The aim of this study was to determine plasma concentrations of AAGP after delivery of preterm and term infants, and to investigate correlations between AAGP and gestational age, birth weight, gender, and mode of delivery. METHODS: In this prospective observational study, blood was sampled from umbilical cords of 70 newborn infants born at gestational weeks 27-42 immediately after delivery. Blood samples were subsequently analysed for AAGP plasma concentrations with an immunoturbidimetric assay. RESULTS: We found higher concentrations of AAGP in infants born vaginally compared with those who were delivered by elective Caesarean section [median (inter-quartile range) 0.189 g litre-1 (0.142-0.263 g litre-1) vs 0.110 g litre-1 (0.094-0.157 g litre-1; P=0.0003)], respectively. There was a correlation between gestational age and AAGP concentrations (r=0.50; P=0.011), with significantly higher concentrations in the more mature infants. Gender and birth weight did not appear to influence the plasma concentrations of AAGP. CONCLUSIONS: Alpha-1-acid glycoprotein concentrations in newborns are influenced both by gestational age and mode of delivery. Thus, when dosing local anaesthetics in a parturient, these factors should be taken into account.

Cell-specific nitrogen- and carbon-fixation of cyanobacteria in a temperate marine system (Baltic Sea).

We analysed N2 - and carbon (C) fixation in individual cells of Baltic Sea cyanobacteria by combining stable isotope incubations with secondary ion mass spectrometry (SIMS). Specific growth rates based on N2 - and C-fixation were higher for cells of Dolichospermum spp. than for Aphanizomenon sp. and Nodularia spumigena. The cyanobacterial biomass, however, was dominated by Aphanizomenon sp., which contributed most to total N2 -fixation in surface waters of the Northern Baltic Proper. N2 -fixation by Pseudanabaena sp. and colonial picocyanobacteria was not detectable. N2 -fixation by Aphanizomenon sp., Dolichospermum spp. and N. spumigena populations summed up to total N2 -fixation, thus these genera appeared as sole diazotrophs within the Baltic Sea's euphotic zone, while their mean contribution to total C-fixation was 21%. Intriguingly, cell-specific N2 -fixation was eightfold higher at a coastal station compared to an offshore station, revealing coastal zones as habitats with substantial N2 -fixation. At the coastal station, the cell-specific C- to N2 -fixation ratio was below the cellular C:N ratio, i.e. N2 was assimilated in excess to C-fixation, whereas the C- to N2 -fixation ratio exceeded the C:N ratio in offshore sampled diazotrophs. Our findings highlight SIMS as a powerful tool not only for qualitative but also for quantitative N2 -fixation assays in aquatic environments.

Prevalence and molecular epidemiology of Staphylococcus aureus in Swedish nursing homes - as revealed in the SHADES study.

SUMMARY: Knowledge of carriage and population dynamics of Staphylococcus aureus is crucial for infection risk assessment and to reveal transmission patterns of strains. We report the prevalence and molecular epidemiology of S. aureus in elderly people (n = 290) living in nursing homes in three cities in the south of Sweden. The overall carriage prevalence rate was 48% when results from nares (31%) and throat (34%) samples were combined. Common spa types were equally distributed but a frequent type, t160, was found only in one of the regions. Carriage of different spa types was detected in 23% of individuals and antimicrobial resistance rates were higher in S. aureus isolates from those carrying more than one spa type. Five of the 21 individuals who carried different spa types were colonized simultaneously with resistant and non-resistant strains. Seventeen per cent of the individuals carried S. aureus of the same spa type on all occasions. Methicillin resistance was not detected. In conclusion we found a high prevalence of S. aureus in this elderly population with a high rate of dual colonization with different spa types. We also found signs of institutional spread of one strain.

Specific demonstration of drug-induced tumour cell apoptosis in human xenografts models using a plasma biomarker.

Pharmacodynamic (PD) assays should be used before advancing new drugs to clinical trials. Most PD assays measure the response to drugs in tissue, a procedure which requires tissue biopsies. The M30-Apoptosense ELISA is a PD biomarker assay for the quantitative determination of caspase-cleaved cytokeratin 18 (CK18) released from apoptotic carcinoma cells into blood. We here demonstrate that whereas the M30-Apoptosense ELISA assay detects human caspase-cleaved CK18, the mouse and rat CK18 caspase cleavage products are detected with low affinity. The M30-Apoptosense ELISA therefore facilitates the determination of drug-induced apoptosis in human tumour xenografts in rodents using plasma samples, largely independently from host toxicity. Increases of caspase-cleaved CK18 were observed in plasma from different carcinoma xenograft models in response to anticancer drugs. The appearance caspase-cleaved CK18 in plasma was found to reflect formation of the caspase-cleaved epitope in FaDu head-neck carcinomas and in cultured cells. The M30-Apoptosense assay allows determination of tumour response in blood from xenograft models and from patients, providing a powerful tool for translational studies of anticancer drugs.

Induction of early light-inducible protein gene expression in Pisum sativum after exposure to low levels of UV-B irradiation and other environmental stresses.

Plants are constantly subjected to environmental changes and have developed various defence mechanisms to facilitate their continued existence. Pisum sativum plants were exposed to low levels of UV-B radiation and ELIP (early light-inducible proteins) mRNA, with a probable protective function, was rapidly and strongly induced during this type of stress. To our knowledge, this is the only photosynthetic gene that is up-regulated following exposure to UV-B, and this result has to be compared with studies predominantly reporting down-regulation by UV-B of genes encoding proteins localised in the plastid. The expression pattern of ELIP mRNA in pea was also investigated during salt, wounding and ozone stress. The transcript levels of ELIP were induced after the salt and wounding treatments but not during ozone fumigation.

Fecal carriage of vancomycin- and ampicillin-resistant Enterococci observed in Swedish adult patients with diarrhea but not among healthy subjects.

During a 1-y prospective study between 1 October 1996 and 30 September 1997, fecal samples from 786 adult patients with diarrhea and 203 healthy control subjects were screened for vancomycin-resistant Enterococci (VRE) and ampicillin-resistant Enterococci (ARE). The carriage rates of VRE and ARE were 0.4% and 6%, respectively among patients and 0% among controls. The 3 VRE isolates were all VanA and were obtained from patients who had been abroad (Thailand, Spain, France) within the previous 3 months. Thirteen of the 45 patients with ARE (29%) had been abroad within 2 weeks of the onset of diarrhea. These findings suggest a potential risk of introduction of antibiotic-resistant Enterococci in Swedish hospitals by patients receiving treatment for diarrhea after traveling abroad.

[Cannabis and pregnancy]. / Cannabis og graviditet.

In two Copenhagen University hospitals 12,885 pregnant women, seen during the period 1.8.1992 to 30.04.1995, answered questionnaires regarding consumption of alcohol, tobacco, cannabis and other drugs. The prevalence of cannabis use was 0.8%. Women using cannabis but no other illicit drugs were each retrospectively matched with four randomly chosen pregnant women in the same period and the same age group and with same parity. Eighty-four cannabis users were included. These women were socioeconomically disadvantaged and had a higher prevalence of present and past use of alcohol, tobacco and other drugs. No significant difference in pregnancy, delivery or puerperal outcome was found. Children of women using cannabis were 150 g lighter, 1.2 cm shorter and had 0.2 cm smaller head circumference than the control infants. Controlling for the child's sex and maternal use of alcohol did not eliminate the significant differences in birthweight and length; however, they were eliminated by controlling for maternal tobacco smoking. It is concluded, that the use of cannabis is not a major prognostic factor regarding the outcome of pregnancy, but is an indicator of low socioeconomic status and use of other substances.

Biokinetics and radiation doses for carbon-14 urea in adults and children undergoing the Helicobacter pylori breath test.

The long-term biokinetics and dosimetry of carbon-14 were studied in nine adults and eight children undergoing carbon-14 urea breath test for Helicobacter pylori (HP) infection. The elimination of 14C via exhaled air and urine was measured with the liquid scintillation counting technique and with accelerator mass spectrometry. After the subjects had been given 110 kBq 14C-urea (children: 55 kBq) orally, samples of exhaled air were taken up to 180 days after administration and samples of urine were collected up to 40 days. Sixteen of the subjects were found to be HP-negative. In these subjects a total of 91.1%+/-3.9% (mean of adults and children +/- standard error of the mean) of the administered 14C activity was recovered. The majority of the administered activity, 88.3%+/-6.2% in adults and 87.7%+/-5.0% in children, was excreted via the urine within 72 h after administration. A smaller fraction was exhaled. In adults 4.6%+/-0.6% of the activity was exhaled within 20 days and in children 2.6%+/-0.3%. Uncertainties in the biokinetic results are mainly due to assumptions concerning endogenous CO2 production and urinary excretion rate and are estimated to be less than 30%. The absorbed dose to various organs and the effective dose were calculated using the ICRP model for urea and CO2. The urinary bladder received the highest absorbed dose: in adults, 0.15+/-0.01 mGy/MBq and in children of various ages (7-14 years), 0.14-0.36 mGy/MBq. The findings indicate that an investigation with 14C-urea gives an effective dose to adults of 2.1+/-0.1 microSv (for 110 kBq) and to children of 0.9-2.5 microSv (for 55 kBq). From a radiation protection point of view, there is thus no reason for restrictions on even repeated screening investigations with 14C-urea in whole families, including children.

Growth and clonogenic assays compared for irradiated MCF-7 and Colo-205 cell lines.

Clonogenic assays have been the golden standard for the assessment of cytotoxic injury from irradiation or drugs. Since such assays are time consuming, growth assays, often with automatic quantifying equipment, are frequently used. Since these procedures do not immediately reflect loss of clonogenic capacity, it was considered important to validate the two procedures using gamma-irradiation (0, 2 and 4 Gy) of two human cell lines (MCF-7 and Colo-205). The cells were growing exponentially in 96-well plates and crystal violet staining resulted in optical densities proportional to cell number. The homogeneity of optical densities within the plates was optimal if the wells to be measured were surrounded by liquid-containing ones. The slopes of the exponential growth curves were decreased upon irradiation. An "apparent cell survival", the mean of the three lowest ratios between irradiated and control cells, was defined. It was compared with the SF2 and SF4 as found in parallel Courtenay-Mills assays. In this work we found a modest underestimation of cell survival using the growth assay, ranging from 0 to 17 per cent in absolute terms.

Influences of intentionality at encoding and retrieval on memory in adulthood and old age.

This research investigated whether different memory functions are differentially affected by the adult aging process. Four groups of normal adults (18-35, 60-68, 69-78, and 79-91 years of age) were presented with a set of pictures of faces with first names and surnames. Subjects were instructed to memorize the faces and the surnames for subsequent memory tests. Memory performance was assessed in four ways: stem completion of surnames; recognition of faces; recognition of surnames and recognition of first names. These memory tests varied in terms of intentionality at encoding and retrieval. The stem completion task involved intention at encoding, but not at retrieval, and thus served as a measure of implicit memory. With respect to the three explicit memory tasks, recognition of faces and surnames involved intention at both encoding and retrieval, whereas recognition of first names involved intention at retrieval, but not at encoding. Results indicated no age-related differences in implicit memory, as assessed by the stem completion test. In addition, there was an age-related deficit in recognition of faces and surnames, although there were no age-related differences in recognition of first names. The overall pattern of results suggests that age-related deficits in memory may be most likely to occur when there are demands of conscious mental activity at encoding and retrieval.

Differences in binding of platelet factor 4 to vascular endothelium in vivo and endothelial cells in vitro.

The binding of fluorescein-labelled recombinant human platelet factor 4 (rhPF4) to the vasculature of the hamster cheek pouch in vivo was compared with that to cultured endothelial cells (EC) from human umbilical veins (HUVEC) and arteries (HUAEC) and from human aorta (HAEC). In vivo data: systemically injected rhPF4 rapidly disappeared from plasma in a biphasic pattern (t1/2 = 2 and 41 min). High intensity non-uniform binding of rhPF4 occurred at short specific sites along both arterioles and venules. The length of the intense sites was 76 +/- 46 microns and their frequency was 10 +/- 4 per cm2 cheek pouch. Heparin was injected at 4 and 9 min, but not 30 min, post-rhPF4 displaced most of the high intensity labelling indicating internalization with time. Neither pretreatment with more than 50-fold excess of unlabelled rhPF4 nor histamine- or LTB4-induced vascular macromolecular leakage changed the frequency of short intense sites. In vitro data: uniform time-dependent intense binding of rhPF4 occurred in a similar fashion in subconfluent HUVEC, HUAEC and HAEC. All cell types showed nuclear staining, demonstrating internalization. When heparin was given to EC prior to rhPF4, binding was delayed in time but not blocked. In conclusion, rhPF4 does not bind uniformly with high intensity along pre- and post-capillary vessels of the hamster cheek pouch in vivo as predicted by the rhPF4-labelling of subconfluent (migrating/proliferating) human EC in vitro. The short infrequent sites of intense rhPF4-labeling in vivo may represent regions of endothelial cell migration/proliferation similar to subconfluent EC in culture.

[HIV antibody positive children in Denmark]. / Børn med HIV-antistoffer i Danmark.

The AIDS-committee of The Danish Society of Paediatrics has done a nation-wide study among infants and children under the age of 15 with AIDS or HIV-antibodies in preparation for planning prevention and treatment. Clinical data have been collected from the Departments of Paediatrics and Infectious Diseases, Haemophilia, Dermatology and Internal Medicine up to 1 March 1993. The study includes 44 infants with a risk of vertical transmission from the mother and 16 children with haemophilia. No cases were found to be infected by blood-transfusion. Twenty of the 44 infants with congenital HIV-antibodies were HIV-infected. Seven of them died from AIDS, 10 currently have AIDS and three are asymptomatic. Seventeen infants are well and HIV-antibody negative after the age of 18 months. Seven infants still have unclarified status, but all are well. Three of the patients with haemophilia are dead. The 13 others do not have AIDS. It is surprising that most of the infected infants' mothers were not known to be infected before the infants got sick. Thus infected infants exist in families who are not suspected to be HIV-infected. The AIDS-committee of The Danish Society of Paediatrics has proposed recommendations for HIV-testing of infants and children. HIV-infected families need comprehensive psychosocial care. The risk-factor from blood-transfusion is now eliminated, but vertical transmission will continue to be a risk-factor. The size of the problem in Denmark will not be known until an epidemiological study of pregnant women has been conducted.

Predictors of prose recall in adulthood and old age.

One group of young adults and three groups of older adults (young-old, old, old-old) were examined in immediate recall of random and organizable words, and immediate and delayed recall of prose passages. Results showed that all groups of older adults recalled less from the prose passages and the word recall tasks than the younger adults, although there were no performance differences among the three older samples. As well, all age groups showed a similar increase in recall of organizable words compared with random words, and all age groups showed parallel forgetting curves in prose recall. These results suggest that all age groups utilized the organizational support to the same extent, and that forgetting rate was not influenced by age. Regression analyses showed that recall of random and organizable words, education, vocabulary and age all contributed to prose recall performance. Most important, the importance of markers of strategy use (word recall tasks) for prose recall decreased from early to late adulthood, whereas the importance of a semantic memory marker (vocabulary) showed the opposite pattern.

Antibiotic susceptibility, serovars and auxotypes of gonococcal isolates in Stockholm. Relation to geographical origin of the infection.

The antibiotic susceptibility, serovars and auxotypes were investigated in gonococcal strains isolated from all patients with gonorrhoea during one year in Stockholm, Sweden. The results were correlated to geographical origin of the infection. A total of 394 gonococcal strains were isolated from 392 patients, 135 (34%) women and 257 (66%) men. Beta-lactamase-producing gonococcal strains (PPNG) were isolated from 5% of the women and 16% of the men. Men had acquired their infection abroad more often than women (54% vs 33%) (P < 0.001). The majority (81%) of the PPNG infections were imported. Some serovars and auxotypes were more common among imported strains than among indigenous ones. All strains were sensitive to spectinomycin and 2 strains had decreased susceptibility to norfloxacin and ciprofloxacin. Decreased susceptibility to benzylpenicillin, ampicillin, doxycycline and cefuroxime was related to the geographical origin of the strains with strains imported from regions other than Europe being the most resistant.

Syphilis, gonorrhoea and genital chlamydial infection in a Somali village.

A total of 767 sera were collected from 187 men, 200 women and 380 children in a Somali village, Jambaluul. All sera were tested for syphilis serological markers by Venereal Diseases Research Laboratory (VDRL) and Treponema pallidum Haemagglutination Assay (TPHA). Sera positive for both or either of these tests were further analysed for the presence of specific IgM antibodies by Solid Phase Haemadsorption Assay (SPHA). A high and almost equal prevalence of TPHA positivity was found in men and women; 24% and 22.5%, respectively, and IgM antibodies were found in 3% and 4%, respectively. TPHA positivity significantly increased with age. Thus more than half of the villagers at the age of 45 years or more were TPHA positive. One percent of the children were TPHA positive. From all adults aged 15 years and above urogenital specimens were also taken for Chlamydia trachomatis antigen detection with an enzyme-amplified immunoassay (IDEIA) and Neisseria gonorrhoeae culture. Chlamydial genital infection was found in 6% of the men and 18% of the women. All gonococcal cultures were negative.

[Children and AIDS]. / Børn og AIDS.

Children suffering from HIV-infection is a serious and increasing problem all over the world. The pediatric AIDS cases are usually transmitted through vertical transmission from a HIV-infected mother to the fetus during pregnancy, but it is not possible before the age of 15 months to decide with certainty whether the infant is infected or not. The risk of HIV-transmission from mother to fetus is about 50 per cent. The prognosis of the infected infants are very bad, the morbidity and mortality are high. In USA 60 per cent of the infants with congenit HIV-infection have died before the age of 2 years. The progress of HIV-infection in infants and children is characterized by bacterial infections with subsequent sepsis, neurological symptoms and regression of the psychomotor development. Most of the families are basically suffering from severe psychosocial problems eg drug abuse and at least one of the parents is HIV-infected. A family with a HIV-antibodypositive child is a family suffering from crises, illness, lack of resources and social isolation, and is therefore in need of medical, psychological and social treatment and support. It is urgent to help these children and their families through interdisciplinary intervention to give the children an optimal quality of life. To obtain this it is necessary with interdisciplinary comprehensive programs and multidisciplinary collaboration in the community. And in these programs it is important to prioritate the primary prophylaxis in trying to reduce the number of infants born in risk of HIV-infection.

Investigation of 89 children born by drug-dependent mothers. I. Neonatal course.

Among 89 infants born by opiate- and methadone-addicted mothers 20% were preterm and 31% were light for gestational age. Mean gestational age and birth weight were lower in infants of mothers who had taken mainly opiates compared with infants of mothers who had taken mainly methadone. Preterm labor was more frequent among women who had been acutely withdrawn on methadone within the last month before birth than among women who were maintained on methadone at birth. 85% of the newborns had withdrawal symptoms and 12% had convulsions the severity of which was not correlated with the type of drug abuse. The duration of withdrawal, however, correlated with the amount of methadone taken by the mother at birth. 20% had signs of perinatal asphyxia and had an increased frequency of neonatal convulsions. These babies represent a special high-risk group of newborns. Prevention, therapy and care demand extraordinary combined efforts by politicians, social welfare personnel, midwives, doctors and nurses.