Nanosilver/DCOIT-containing surface coating effectively and constantly reduces microbial load in emergency room surfaces

BACKGROUND

Colonization of near-patient surfaces in hospitals plays an important role as a source of healthcare-associated infections. Routine disinfection methods only result in short-term elimination of pathogens.

AIM

To investigate the efficiency of a newly developed antimicrobial coating containing nanosilver in long-term reduction of bacterial burden in hospital surfaces to close the gap between routine disinfection cycles.

METHODS

In this prospective, double-blinded trial, frequently touched surfaces of a routinely used treatment room in an emergency unit of a level-I hospital were treated with a surface coating (nanosilver/DCOIT-coated surface, NCS) containing nanosilver particles and another organic biocidal agent (4,5-dichloro-2-octyl-4-isothiazolin-3-one, DCOIT), whereas surfaces of another room were treated with a coating missing both the nanosilver- and DCOIT-containing ingredient and served as control. Bacterial contamination of the surfaces was examined using contact plates and liquid-based swabs daily for a total trial duration of 90 days. After incubation, total microbial counts and species were assessed.

FINDINGS

In a total of 2880 antimicrobial samples, a significant reduction of the overall bacterial load was observed in the NCS room (median: 0.31 cfu/cm²; interquartile range: 0.00-1.13) compared with the control coated surfaces (0.69 cfu/cm²; 0.06-2.00; P < 0.001). The nanosilver- and DCOIT-containing surface coating reduced the relative risk of a critical bacterial load (defined as >5 cfu/cm²) by 60% (odds ratio 0.38, P < 0.001). No significant difference in species distribution was detected between NCS and control group.

CONCLUSION

Nanosilver-/DCOIT-containing surface coating has shown efficiency for sustainable reduction of bacterial load of frequently touched surfaces in a clinical setting.

New quantitative automated model to simulate bacterial dissemination in human tissue during irrigation of contaminated wounds

This study presents a simple and cost-effective model using microparticles to simulate the bacterial distribution pattern in soft tissue after low- and high-pressure irrigation. Silica coated iron microparticles [comparable diameter (1 µm) and weight (0.8333 pg) to Staphylococcus aureus] were applied to the surface of twenty fresh human muscle tissue samples in two amputated lower legs. Particle dissemination into deep tissue layers as an undesired side effect was investigated in four measuring fields as positive control (PC) as well as after performing pulsatile high-pressure (HP, 8 measuring fields) and low-pressure flushing (LP, 8 measuring fields). Five biopsies were taken out of each measuring field to get a total number of 100 biopsies. After histological and digital image processing, the specimens were analysed, and all incomplete sections were excluded. A special detection algorithm was parameterised using the open source bioimage analysis software QuPath. The application of this detection algorithm enabled automated counting and detection of the particles with a sensitivity of 95 % compared to manual counts. Statistical analysis revealed significant differences (p < 0.05) in our three different sample groups: HP (M = 1608, S = 302), LP (M = 2176, SD = 609) and PC (M = 4011, SD = 686). While both HP and LP flushing techniques are able to reduce the number of bacteria, a higher effectiveness is shown for HP irrigation. Nevertheless, a challenge for the validity of the study is the use of dead tissue and therefore a possible negative influence of high-pressure irrigation on tissue healing and further dispersion of particles cannot be evaluated.

Timing of anterior cruciate ligament reconstruction within the first year after trauma and its influence on treatment of cartilage and meniscus pathology

PURPOSE

Anterior cruciate ligament (ACL) ruptures are often associated with primary meniscal and cartilage lesions. Late reconstruction of ACL-deficient knees may increase the risk of developing secondary meniscal and cartilage lesions; hence, the timing of ACL repair is of the utmost importance. Because meniscus outcome is also a potential predictor for osteoarthritis (OA), this study compared ACL repair within the first 6 months after injury to that of surgery conducted 7-12 months after injury with regard to the incidence of meniscal and cartilage lesions.

METHODS

This prospective cross-sectional study included all complete isolated primary ACL ruptures treated in our institution within 1 year after trauma over a 12-month period. Exclusion criteria were revision ACL, complex ligament injuries, previous knee surgery, and missing injury data. Cartilage lesions were classified according to the score established by the International Cartilage Repair Society (ICRS score) and meniscal tears according to their treatment options.

RESULTS

Two hundred and thirty-three of 730 patients (162 men, 71 women) with ACL repair met the inclusion criteria. 86.3 % of surgical interventions were conducted within 6 months and 13.7 % after 6 months of trauma. Severe cartilage lesions grade III-IV did not significantly differ between the different time points of ACL repair (<6 months 39.9 %; >6 months 31.3 %; p = n.s.). Medial meniscus lesions received significantly higher meniscal repair in early compared to delayed ACL repair. Significantly higher rate of meniscal repair of the medial meniscus was seen in cases of early ACL repair compared to delayed (<6 months 77.2 %, >6 months 46.7; p = 0.022). The rate of medial meniscal repair in early ACL repair was significantly higher for women (89.5-0 %; p = 0.002), however, not for men (73.3-53.8 %; p = n.s.). No differences were found for lateral meniscal lesions, with regard to neither the different time points (p = n.s.) nor the sex (p = n.s.).

CONCLUSIONS

Because of the significantly higher rate of prognostically advantageous meniscal repair, the recommendation for an ACL reconstruction within 6 months after trauma was made to preserve the meniscus and reduce the risk of developing OA.

LEVEL OF EVIDENCE

Prospective cross-sectional cohort study, Level II.

Posterolateral fusion in acute traumatic thoracolumbar fractures: a comparison of demineralized bone matrix and autologous bone graft

INTRODUCTION Alternative fusion expanders are in clinical use for instrumented posterolateral fusion (PLF) to avoid donor site morbidity in autologous bone graft (ABG) harvesting. Purpose of this study was to evaluate demineralized bone matrix (DBM) in PLF as alternative to the gold standard of ABG in acute traumatic vertebral body fractures of the thoracolumbar spine. MATERIAL AND METHODS We retrospectively identified 101 patients with acute traumatic vertebral body fractures of the thoracic and lumbar spine who were treated with instrumented PLF in our level one trauma center between 2005 and 2011. Patients with a primary paraplegia, osteodepriving disease or loss to follow-up had been excluded. Until August 2008, autologous bone graft harvested from the posterior iliac crest was used in PLF (control group n = 46). Starting September 2008, DBM was used as fusion expander in PLF (study group n = 16). Clinical and radiological evaluation was performed with a minimum followup of 18 months to assess the clinical and radiological outcome. RESULTS We found a fusion rate of 94% in patients undergoing PLF with the use of DBM and 100% with the use of ABG. There was one major complication of deep infection in the DBM group and two cases of superficial wound infection in the ABG group. We discovered a trend of reduced operating time with the use of DBM. CONCLUSIONS DBM leads to a similar fusion rate as the use of ABG in patients undergoing PLF for acute traumatic vertebral body fractures of the thoracic and lumbar spine. DBM is associated with reduced operating time.

LEVEL OF EVIDENCE III

case-control study Key words: demineralized bone matrix instrumented posterolateral fusion, acute traumatic vertebral body fracture, thoracolumbar spine, autologous bone graft.

Contrast enhanced ultrasound (CEUS) and time intensity curve (TIC) analysis in compartment syndrome: first results

OBJECTIVE

Purpose of this study was to monitor changes of microcirculation in acute compartment syndrome using contrast enhanced ultrasound (CEUS) and to assess the modified perfusion with a special quantification software.

METHODS

8 patients with trauma of the lower limb or the upper extremity were enrolled after acute compartment syndrome was diagnosed clinically and by intracompartmental pressure measurement. The qualitative analysis of the corresponding compartment was assessed using B-scan mode and CEUS simultaneously. CEUS was performed using a multifrequence probe (6-9 MHz, LOGIQ E9 GE) after a i.v. bolus injection of 2 × 2.4 ml contrast agent (SonoVue(®), Bracco, Italy). Digital raw data were stored as cine loops up to 2 minutes. Retrospectively semiquantitative perfusion analysis was performed using time intensity curve analysis and the quantification software QONTRAST(®).

RESULTS

6 out of 8 patients had to be operated due to clinical symptoms and to a pressure perfusion gradient lower than 30 mm Hg. 2 out of 8 were treated conservatively. In all patients haematomas were seen in B-scan mode. No necrosis could be detected. In the TIC analysis low levels of time to peak (20.0 ± 12.1) and area under the curve (118.4 ± 87.8) were observed in acute compartment syndrome. Similarly results have been obtained using the perfusions parameter PEAK (11.1 ± 5.7), time to PEAK (14.7 ± 9.7), regional blood volume (257.1 ± 192.6), and regional blood flow (12.1 ± 6.5) in QONTRAST(®) perfusion software.

CONCLUSION

CEUS may be capable of differing between acute compartment syndrome and imminent compartment syndrome.

Osteocutaneous free flaps: a critical analysis of quantitative evaluation of bone microcirculation with contrast-enhanced high resolution ultrasound (hrCEUS) and TIC analysis

PURPOSE

Osteocutaneous free flaps (OFF) are widely used to reconstruct large bone defects in trauma and cancer surgery. Currently no monitoring method is available to detect blood circulation around and inside the bone after transplantation. Therefore we used for the first time contrast-enhanced high-resolution ultrasound (hrCEUS) to gain evidence for the microcirculation of the transplanted bone.

MATERIALS AND METHODS

15 patients transplanted with OFF because of large bone defects at different sites were examined postoperatively with hrCEUS with a high resolution linear probe (6-9 MHz, LOGIQ E9/GE) and a bolus injection of 2.4 ml of contrast agent (SonoVue®, Bracco, Italy). Operation and examination were performed by either an experienced plastic surgeon or an experienced ultrasound examiner. Microcirculation of the periost and bone was analyzed in different regions of interest (ROIs) and quantitative microcirculation analysis was performed using time intension curve analysis (TIC). We further analyzed clinical outcome of the patients in respect to revision-surgery, necrosis of the OFF and flap survival as well as viability on standard x-rays 2 months after surgery.

RESULTS

The most representative parameter by TIC analysis of hrCEUS were the area under the curve (AUC) and the time to peak (Ttop). The AUC of the periost and central part of the bone showed a high correlation (Pearson's r = 0.831). Mean AUC for the periost was 163.92 dB ± 49.44 and for the central part of the bone 70.42 dB ± 25.33. The Ttop of the periosteal ROI was 33.04 sec. ± 6.71 and the bone ROI 41.01 sec. ± 9.24. There was a high correlation of the Ttop of the periost and bone (Pearson's r = 0.937). One revision had to be performed due to haematoma and microcirculation defect of the distal part of the transplanted bone graft which was detected early by hrCEUS and the distal part of the avital bone could be removed timely.

CONCLUSION

For the first time we could show that hrCEUS is a reliable method to evaluate the viability of OFF. The AUC and Ttop seem to be a valuable parameter to detect the microcirculation around and inside the bone transplant.

Hepatitis C in Austria 1993-2000: reporting bias distort HCV epidemiology in Austria

From 1993 to 2000 in Austria, the notification system registered 2232 cases of hepatitis C whereas 10 607 hospital cases were reported in the hospital discharge register (HDR). These differences can be explained by under-reporting due to lax reporting behaviour and stigma associated with this disease. The distribution of HCV infection varied geographically. The notification data showed the highest incidence rates in Tyrol, while HDR data showed highest hospitalisation rates in Vienna and Lower Austria. This study highlights the urgent need for a clear case definition at the national level and an electronic reporting system.

Malaria in Austria 1990-2000

In Austria, between 1990 and 2000, 924 travel related malaria cases were reported (mean = 84/year). No significant decreasing or increasing trends were observed. P. falciparum (n=517; 55.9%) accounted for the highest number of cases followed by P. vivax or ovale (n=321; 34.7%) and P. malariae (n=29; 2.2%). Most infections were contracted in highly endemic malaria regions (n=686; 74.2%) and most cases were reported from the largest counties: Vienna (n=336, 36.4%), Styria (n=156, 16.8%), and Lower Austria (n=151, 16.3%). Overall, 12 deaths occurred, most were caused by P. falciparum (n=9, 75%; case fatality rate: 1.9%). Data on chemoprophylaxis was available for 752 cases (81.4%) but only half of them (n=367, 48.8%) gave detailed information on the drug used. Data on compliance were obtained for only 45.4% of the cases, with only about 60% of patients completing the full course of prophylaxis.

Tuberculosis in Austria 1995–99: geographical distribution and trends

A descriptive analysis of routine surveillance data on tuberculosis (TB) from 1995 to 1999 was performed in Austria. The federal states of Vienna and Upper Austria showed the highest yearly incidences for all five years. In general, however, a decrease of the yearly incidence was observed for all federal states except for Carinthia (where there was a small increase of 3.2 %). In the cities of Vienna, Linz, Wels, Salzburg, Klagenfurt and St-Pölten, as well as in the regions of Eastern Tyrol, Southern Carinthia, and Southern Burgenland, the incidence was above average (&gt;19 cases/100 000 for each). The number of cases per year and per district reported by the statutory reporting system were clearly in excess of those reported by hospitals. The comparison of the two datasets, however, showed a highly significant regional correlation of age standardised morbidity rates at district level. The findings are prone to reporting bias and might not reflect the real TB situation. The responsible health authorities should therefore consider the results as a 'working hypothesis’ in order to review the reporting behaviour at district level.

Tuberculosis in Austria 1995-99: geographical distribution and trends

A descriptive analysis of routine surveillance data on tuberculosis (TB) from 1995 to 1999 was performed in Austria. The federal states of Vienna and Upper Austria showed the highest yearly incidences for all five years. In general, however, a decrease of the yearly incidence was observed for all federal states except for Carinthia (where there was a small increase of 3.2 %). In the cities of Vienna, Linz, Wels, Salzburg, Klagenfurt and St-Pölten, as well as in the regions of Eastern Tyrol, Southern Carinthia, and Southern Burgenland, the incidence was above average (>19 cases/100,000 for each). The number of cases per year and per district reported by the statutory reporting system were clearly in excess of those reported by hospitals. The comparison of the two datasets, however, showed a highly significant regional correlation of age standardised morbidity rates at district level. The findings are prone to reporting bias and might not reflect the real TB situation. The responsible health authorities should therefore consider the results as a 'working hypothesis in order to review the reporting behaviour at district level.

Centromere and telomere redistribution precedes homologue pairing and terminal synapsis initiation during prophase I of cattle spermatogenesis

Alterations in nuclear topology associated with meiotic chromosome pairing were studied in premeiotic cells and spermatocytes I of adult bovine males. To this end, we performed FISH with chromosome, pericentromeric satellite-DNA and telomere-specific probes in combination with immunostaining of synaptonemal complex proteins (SCP3, SCP1) on testis tissue sections. Nuclei of premeiotic cells (spermatogonia) exhibited a scattered telomere distribution while pericentromeres formed a few intranuclear clusters. We observed that the chromosome pairing process in cattle prophase I is preceded by repositioning of centromeres and telomeres to the nuclear periphery during preleptotene. Clustering of chromosome ends (bouquet formation) was observed during the transition from leptonema to zygonema and coincided with pairing of a sub-centromeric marker of bovine chromosomes 7. Dissolution of bouquet topology during zygonema left perinuclear telomeres scattered over the nuclear periphery at pachynema. SCP3 staining in frozen tissue sections revealed the appearance of this axial element protein in intranuclear aggregates during preleptotene, followed by extensive axial element formation during leptotene. Synapsis as revealed by SCP1 staining initiated peripherally at earliest zygotene, at this stage nuclei still contained numerous SCP3 clusters. Our observations reveal prominent non-homologous satellite-DNA associations in spermatogonia and indicate the conservation of topological features of the meiotic chromosome pairing process among mammals. The comparison of telomere dynamics in mouse and cattle prophase I suggests that a larger number of chromosomes prolongs the duration of the bouquet stage.

[Injury pattern and overuse stress syndrome in young sport climbers]

The rapidly growing interest in sports climbing in recent years among young climbers raises the question about the risk of injuries and overstrain syndromes in this group. This paper investigates injuries and overstrain syndromes of 99 adolescent climbers aged between 8 and 19 years. The authors interviewed climbers from Austria, Germany and Switzerland. Besides the type and pattern of injuries and overstrain syndromes, the level and duration of climbing, intensity of training and gender were recorded as potential risk factors. 47 climbers were asked about setting up fingers on small holds, which is considered a main reason for epiphyseal injuries of fingers in the literature. Injuries and overstrain syndromes, as well as their frequency and pattern are reported and classified. Descriptive data analysis and statistical models are used to assess the influence of risk factors. Among the potential risk factors only the climbing level has a significant influence on the risk of injuries and overstrain syndromes (p = 0.0427). Furthermore the risk of injuries and overstrain syndromes in the area of the fingers is significantly higher for climbers who reported setting up fingers on small holds (OR = 8.24, p = 0.0022). Finally we found a higher frequency of injuries and overstrain syndromes in lower extremities (43% of all injury and overstrain occurrences) and a lower frequency of injuries and overstrain syndromes in general (43% of all the climbers under investigation) compared to other studies. As a result special guidelines for training and competition are given. In order to increase the accuracy of the reports and to investigate long-term effects we recommend a study with clinical assessment and a longer period of observation.

Spatial analysis of Percutaneous Transluminal Coronary Angioplasty (PTCA) in Austria

STUDY OBJECTIVES

To investigate the geographical distribution of Percutaneous Transluminal Coronary Angioplasty (PTCA) and morbidity for coronary heart disease, angina pectoris and myocardial infarction by spatial analysis of the standardized morbidity rates (SMR) on district level. To identify clusters by Moran's I Statistic and the Regional Spatial Autocorrelation Coefficient (RSAC) of Munasinghe and Morris. To investigate demand factor morbidity and supply factor health care infrastructure on the district level as reasons for geographical disparity. To describe characteristics of the cluster population and intervention centres.

STUDY DESIGN

Retrospective record linkage study.

SETTING

All hospitals and cardiological centres in Austria (n = 150) which performed the Minimum Basic Data Set (MBDS).

PATIENTS

All Austrian residents who were diagnosed for myocardial infarction, coronary heart disease or angina pectoris in 1995 (n = 87,174).

MEASUREMENTS AND MAIN RESULTS

One 'positive' PTCA cluster (all SMRs > or =0.96) and one 'negative' PTCA cluster (all SMRs < or =0.59) were identified. They differed significantly in morbidity rate, intervention rate and available cardiological beds. The tendency to inverse relation between PTCA utilization and morbidity in the 'negative' cluster supported the thesis of 'inverse care law'. Austrianwide no significant correlation was found between the SMR of PTCA-application and both demand factor and supply factors. Nevertheless, differences between the clusters concerning number and capacity of intervention centres and density of specialists pointed to supply factors as reasons for geographical disparity. The ongoing trend of steady expansion of existing intervention centres and establishment of new ones will reduce the extent of geographical variation in future.

Effects of morbidity, age, gender and region on percutaneous transluminal coronary angioplasty (PTCA) utilisation

OBJECTIVES

To investigate changes in the use of PTCA application in respect to morbidity, gender, region and age, and to investigate the morbidity as related to geographical variation.

STUDY DESIGN

Retrospective record linkage study.

SETTING

All hospitals and cardiological centres (n = 156) which performed the Minimum Basic Data Set (MBDS).

PATIENTS

All Austrian residents who were diagnosed for myocardial infarction, coronary heart disease or angina pectoris in 1993-1995 (1993: n = 73.077; 1994: n = 80.173; 1995: n = 84.896).

MEASUREMENTS AND MAIN RESULTS

The intervention rate (IR = PTCA/indication) increased from 0.03-0.04 (33%) between 1993 and 1995 with differences in genders (males: 24%, females: 27.7%) and regions (Vorarlberg: -7.5%, Burgenland: 65.3%). Male morbidity started to increase at about 60 y and female morbidity at about 70 y. Morbidity as a demand factor did not correlate with PTCA application. The intervention rate was significantly lower for females in Austria in general (P < 0.001) as it was in every Federal State (P < 0.001). This pattern was constant during 1993-1995 with the highest difference in Salzburg and the lowest in Styria. Austrian men were about three times more likely to have received PTCA application than women (crude Odds Ratio = 2.8, 95% CI = 2.6-3, P-value < 0.001). Logistic regression modelling revealed age as main confounder (adjusted Odds Ratio = 1.36, 95% CI = 1.31-1.42, P < 0.001). The > or = 5% intervention rate peak was between 30-75 y for males and between 30-65 y for females whereas morbidity of > or = 1% started for males at about 50 y and for females at about 60 y. Marked geographical differences of the intervention rate were observed (Upper Austria, Salzburg IR = 0.07, Styria IR = 0.02) but could not be explained by the demand factor morbidity (Pearson's correlation coefficients 1993: 0.039, P = 0.71; 1994: 0.155, P = 0.133; 1995: 0.087, P = 0.399).

CONCLUSIONS

The highest intervention rates were in the age groups with the lowest morbidity. Women received significantly fewer interventions than men by age and region. The demographic strata with lowest use rate were women aged 64 y and more. Marked geographical differences of PTCA application were stated but could not be explained by the demand factor morbidity. Further studies on supply factors as well as on economic and social factors are needed in order to develop public health strategies to guarantee equal utilisation rates for the whole Austrian population.

[Hospitalization of young women after selected cardiovascular and thromboembolic incidents in Austria 1993 and 1994]

The aim of this study is to describe the hospitalization and regional distribution of selected cardiovascular and thrombo-embolic events (cardiac infarction, cerebral strokes, deep vein thromboses, pulmonary embolism) of young women in Austria in the years 1993 and 1994, and to collect basic epidemiologic data for the study of the side effects of oral contraceptives. The calculated hospitalization rates are based on the Austrian hospitals' discharge records of 1993 and 1994. The persons concerned are women aged between 15 and 44 who live in Austria. The results of the study reveal that--in 1993--of the above mentioned group 51 out of 100,000 inhabitants were hospitalized because of the selected cardiovascular and thromboembolic events: 4/100,000 had a cardiac infarction, 5/100,000 had a stroke, 17/100,000 had a pulmonary embolism, and 27/100,000 suffered a deep vein thrombosis. In 1994 the counted cases per 100,000 inhabitants were 48, out of which 4/100,000 where cardiac infarcts, 5/100,000 strokes, 16/100,000 pulmonary embolism, and 25/100,000 deep vein thromboses.

Systemic hematological effects of granulocyte colony-stimulating factor produced by irradiated gene-transfected fibroblasts

Although long-term expression of therapeutic molecules is necessary for the treatment of permanent deficiencies, short-term expression of therapeutic molecules inducing local or systemic effects is preferable in clinical situations where temporary substitution is the goal. One such clinical setting is the administration of hematopoietic growth factors in cancer chemotherapy-induced myelosuppression. Several plasmid vectors containing the human granulocyte colony-stimulating factor (G-CSF) gene under transcriptional control of different regulatory elements were constructed. In vitro production of G-CSF by nonvirally transfected murine fibroblast clones initially increased after lethal irradiation and was detectable for at least 12 days. We also demonstrate that a single injection of irradiated G-CSF-secreting fibroblasts leads to accelerated hematopoietic recovery and mobilization of committed peripheral blood progenitor cells equivalent to that achieved by twice daily s.c. administration of high doses of recombinant human G-CSF. Using dicistronic vectors, high levels of G-CSF secretion were also obtained in human fibroblasts.

Involving health care workers in screening for alcohol problems

OBJECTIVES

(1) Examine physician and nursing staff compliance with conducting an alcohol screening interview; (2) Compare compliance with the interview with usual physician and nurse assessment of drinking; (3) Examine reasons why drinking information might not be collected.

DESIGN

Residents and nurses were taught how to use an alcohol screening interview and were told by the director of residency training or by the Vice-President for Nursing to administer it to all admitted patients. Data on interviewed patients were compared with medical record data on a randomly selected series of 80 patients who were not interviewed.

SETTING

Teaching hospital in an urban/suburban community.

PATIENTS/PARTICIPANTS

Residents on internal medicine and family practice services; surgical nurses.

MEASUREMENTS AND MAIN RESULTS

Compliance with conducting the interview was low (14.7% of residents' admissions; 13.53% of nurses' admissions). Review of the medical records indicated that some alcohol-related information was recorded in most patients' medical records (physicians recorded information on 94% of patients on the teaching services, nurses on the surgical unit recorded alcohol-related information on 71% of patients). Surgeons and surgical residents recorded alcohol-related information on 30% of their patients. Residents were more likely to interview male than female patients, and residents and nurses tended to interview patients with higher GGTP values.

CONCLUSIONS

(1) Compliance with administering a standardized alcohol screening interview was low. (2) Nurses, and residents in family practice and internal medicine made some assessment of drinking for most patients. Surgeons assessed drinking in a minority of patients. (3) Expressed reasons for not administering the standardized interview included discomfort with the interview, viewing the interview as too time-consuming, or not part of the usual responsibilities of the nurses or residents. Other possible reasons for the low levels of compliance are discussed.

Expression of the Salmonella virulence plasmid gene spvB in cultured macrophages and nonphagocytic cells

Certain serotypes of salmonellae carry virulence plasmids that greatly enhance the pathogenicity of these bacteria in experimentally infected mice. This phenotype is largely attributable to the 8-kb spv regulon. However, spv genes are not expressed while bacteria grow in vitro. We now show that spvB, which is required for virulence, is expressed rapidly after Salmonella dublin is ingested by cultured J774 and murine peritoneal macrophages and that expression is not affected by the alkalinization of intracellular vesicles. The level of induction of spvB is reduced when macrophages are pretreated with gamma interferon. spvB is also expressed in human and canine epithelial cell lines and a human hepatoma cell line. In all cases, spvB expression is dependent on the spvR gene, just as it is in stationary-phase cultures in vitro. These data suggest that spv virulence genes are expressed by intracellular salmonellae in vivo in response to a signal that is common to the intracellular compartments of cells that are invaded by salmonellae.

Periodontal health of the population in eastern Germany (former GDR)

The periodontal status of 1688 inhabitants of eastern Germany (former GDR) was investigated between July 1991 and March 1992, using the CPITN. The results show that only 1.4% of those examined have a healthy periodontal apparatus, whereas 40.1% had some signs of severe periodontitis (CPITN 4). This implies a very high therapy requirement in all age-groups, with 93.1% of 15- to 19-year-olds in need of peridontal treatment (CPITN 1 + 2 + 3 + 4). A comparison between educational qualifications and frequency of brushing or routine dental checks reveals a better level of prophylaxis in the more educated classes. As expected, the CPITN code with good oral hygiene and regular dental checks was significantly lower than with poor oral hygiene and infrequent dental checks. The high prevalence of periodontal disease lends urgency to the development of an extensive prevention concept introduced in childhood.

Plasma concentrations of endotoxin following jugular or portal injections of endotoxin and following gastrointestinal ischemia due to hemorrhage

Endotoxin (LPS) was quantitated in canine plasma using the Limulus amebocyte lysate (LAL) chromogenic testing procedure. The assay was validated for sensitivity (25 pg/ml), recovery (90-110%), intra-assay precision (CV = 5.5), interassay precision (CV = 10), and stability of diluted, heat-treated, frozen samples (greater than or equal to 60 days). Canine plasma samples were analyzed for endotoxin following sublethal IV injections (cephalic and portal, bolus and slow infusion) of LPS. Pharmacokinetic analysis using the two-compartment open model on plasma LPS levels was possible for portal bolus, cephalic bolus, and portal slow infusion dogs. The results revealed that LPS given via cephalic bolus route had a lower clearance rate than LPS given via portal bolus route. Slow infusion of LPS into the portal vein revealed an increased distribution phase t1/2 in plasma and a slower elimination kel and beta rate than observed following a portal bolus injection of LPS. During a clinical endo(to)xemia, LPS enters the circulation slowly, and is therefore probably cleared more slowly; the prolonged low level of LPS may be responsible for many pathophysiological changes observed. Low levels of endotoxin were detected in plasma following hemorrhage, indicating that intestinal ischemia results in low levels of LPS leaking into the circulation.