Observing many researchers using the same data and hypothesis reveals a hidden universe of uncertainty

This study explores how researchers' analytical choices affect the reliability of scientific findings. Most discussions of reliability problems in science focus on systematic biases. We broaden the lens to emphasize the idiosyncrasy of conscious and unconscious decisions that researchers make during data analysis. We coordinated 161 researchers in 73 research teams and observed their research decisions as they used the same data to independently test the same prominent social science hypothesis: that greater immigration reduces support for social policies among the public. In this typical case of social science research, research teams reported both widely diverging numerical findings and substantive conclusions despite identical start conditions. Researchers' expertise, prior beliefs, and expectations barely predict the wide variation in research outcomes. More than 95% of the total variance in numerical results remains unexplained even after qualitative coding of all identifiable decisions in each team's workflow. This reveals a universe of uncertainty that remains hidden when considering a single study in isolation. The idiosyncratic nature of how researchers' results and conclusions varied is a previously underappreciated explanation for why many scientific hypotheses remain contested. These results call for greater epistemic humility and clarity in reporting scientific findings.

Cytomegalovirus infection in renal transplant recipients

We have retrospectively analyzed the incidence of cytomegalovirus (CMV) infection in 250 consecutive renal allograft transplants performed in 244 recipients. The mean follow-up was 35.1+/-25.4 months. Immunosuppression was cyclosporine- or tacrolimus-based triple therapy. CMV infection prophylaxis with ganciclovir for 3 months post transplant was prescribed in CMV-seronegative recipients of allografts from seropositive donors (D+R-) and in all recipients treated with OKT3. CMV antigenemia was monitored by the pp65-antigen assay. Thirteen of 57 D+R- recipients (22.8%) developed CMV antigenemia. One recipient had a breakthrough of CMV antigenemia during ganciclovir prophylaxis; 12 D+R- recipients developed CMV antigenemia 147.5+/-173.8 days after transplantation. Four of 13 (30.7%) D+R- recipients had asymptomatic CMV infection, 8 (61.6%) had CMV infection with non-specific symptoms including fever, and 1 (7.7%) developed CMV pneumonia. Six of 13 (46.1%) D+R- patients had been treated with intensified immunosuppressive therapy before CMV infection. In the low-risk CMV groups (D+R+; D-R+; D-R-), 28 recipients (14.5%) developed CMV antigenemia 42.5+/-15.2 days post transplantation. Ten of the 28 (35.7%) recipients had asymptomatic CMV infection, 17 (60.7%) developed CMV infection with non-specific symptoms, and 1 (3.6%) developed CMV pneumonia. Twenty-one of 28 (75.0%) had intensified immunosuppressive therapy before CMV infection. In conclusion, ganciclovir prophylaxis diminished and delayed the onset of CMV infection but did not totally prevent it from occurring in D+R- renal transplant recipients. Clinicians should be vigilant to the possibility of CMV infection in both seronegative and seropositive recipients, especially after anti-rejection therapy.

Early enteral nutrition within 24h of colorectal surgery versus later commencement of feeding for postoperative complications

BACKGROUND

The role of early postoperative enteral nutrition after gastrointestinal surgery is controversial. Traditional management consist of 'nil by mouth', where patients receive fluids followed by solids when tolerated. Although several trials have implicated lower incidence of septic complications and faster wound healing upon early enteral feeding, other trials have shown opposite results. The immediate advantage of caloric intake could be a faster recovery with fewer complications, to be evaluated systematically.

OBJECTIVES

To evaluate whether early commencement of postoperative enteral nutrition compared to traditional management (no nutritional supply) is associated with fewer complications in patients undergoing gastrointestinal surgery

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials, PUBMED, EMBASE, and LILACS from 1979 (first RCT published) to March 2006. We manually scanned the references from the relevant articles, and consulted primary authors for additional information.

SELECTION CRITERIA

We looked for randomised controlled trials (RCT's) comparing early commencement of feeding (within 24 hours) with no feeding in patients undergoing gastrointestinal surgery. Early enteral nutrition is defined as all oral intakes (i.e. registered oral intake, supplemented oral feeding) and any kind of tube feeding (gastric, duodenal or jejunal) containing caloric content. No feeding is traditional management, defined as none caloric oral intake or any kind of tube feeding before bowel function. The definition 'no nutrition' includes non caloric placebo and water.

DATA COLLECTION AND ANALYSIS

The three authors independently assessed the identified trials, and extracted the relevant data using a specifically developed data extraction sheet. Primary end points of interest were: Wound infections and intraabdominal abscesses, postoperative complications such as acute myocardial infarction, postoperative thrombosis or pneumonia, anastomotic leakages, mortality, length of hospital stay, and significant adverse effects. We combined data to estimate the common relative risk of postoperative complications, and calculated the associated 95% confidence intervals. For analysis, we used fixed effects model (risk ratios to summarise the treatment effect) whenever feasible. The treatment effect on length of stay was estimated using effect size (presented as mean +/- SD). Some outcomes were not analysed but presented in a descriptive way. We used a random effects model to estimate overall risk ratio and effect size.

MAIN RESULTS

We identified thirteen randomised controlled trials, with a total of 1173 patients, all undergoing gastrointestinal surgery. Individual clinical complications failed to reach statistical significance, but the direction of effect indicates that earlier feeding may reduce the risk of post surgical complications. Mortality was the only outcome showing a significant benefit, but not necessarily associated with early commencement of feeding, as the reported cause of death was anastomotic leakage, reoperation, and acute myocardial infarction.

AUTHORS' CONCLUSIONS

Although non-significant results, there is no obvious advantage in keeping patients 'nil by mouth' following gastrointestinal surgery, and this review support the notion on early commencement of enteral feeding.

Antibiotics versus placebo for prevention of postoperative infection after appendicectomy

BACKGROUND

Appendicitis is the most common cause of acute abdominal pain requiring surgical intervention. The cause of appendicitis is unclear and the mechanism of pathogenesis continues to be debated. Despite improved asepsis and surgical techniques, postoperative complications, such as wound infection and intraabdominal abscess, still account for a significant morbidity. Several studies implicate that postoperative infections are reduced by administration of antimicrobial regimes.

OBJECTIVES

This review evaluated the use of antibiotics compared to placebo or no treatment in patients undergoing appendectomy. Will these patients benefit from antimicrobial prophylaxis? The outcomes were described according to the nature of the appendix, as either simple appendicitis (including the non-infectious stage) and complicated appendicitis. The efficacy of different antibiotic regimens were not evaluated.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (Cochrane Library 2005 issue 1); Pubmed ; EMBASE; and the Cochrane Colorectal Cancer Group Specialised Register (April 2005). In addition, we manually searched the reference lists of the primary identified trials.

SELECTION CRITERIA

We evaluated Randomised Controlled Trials (RCTs) and Controlled Clinical Trials (CCTs) in which any antibiotic regime were compared to placebo in patients suspected of having appendicitis, and undergoing appendectomy. Both studies on children and adults were reviewed. The outcome measures of the studies were: Wound infection, intra abdominal abscess, length of stay in hospital, and mortality.

DATA COLLECTION AND ANALYSIS

Eligibility and trial quality were assessed, recorded and cross-checked by two reviewers.

MAIN RESULTS

Forty-five studies including 9576 patients were included in this review. The overall result is that the use of antibiotics is superior to placebo for preventing wound infection and intraabdominal abscess, with no apparent difference in the nature of the removed appendix. Studies exclusively on children and studies examining topical application reported results in favour to the above, although the results were not significant.

AUTHORS' CONCLUSIONS

Antibiotic prophylaxis is effective in the prevention of postoperative complications in appendectomised patients, whether the administration is given pre-, peri- or post-operatively, and could be considered for routine in emergency appendectomies.

Antibiotics versus placebo for prevention of postoperative infection after appendicectomy

BACKGROUND

Appendicitis is the most common cause of acute abdominal pain requiring surgical intervention. The cause of appendicitis is unclear and the mechanism of pathogenesis continues to be debated. Despite improved asepsis and surgical techniques, postoperative complications, such as wound infection and intraabdominal abscess, still account for a significant morbidity. Several studies implicate that postoperative infections are reduced by administration of antimicrobial regimes.

OBJECTIVES

The objective of this review is to evaluate the use of antibiotics with placebo or no treatment in patients undergoing appendectomy. Will these patients benefit from antimicrobial prophylaxis? The outcomes are described according to the nature of the appendix, as either simple appendicitis (including the non-infectious stage) and complicated appendicitis. This review do not attempt to compare the effect of different regimens. That clinical question is addressed in another review undertaken by Bleuer 1999.

SEARCH STRATEGY

We searched The Cochrane Controlled Trials Register (Cochrane Library 2002 issue 4); Pubmed, Embase and the Cochrane Colorectal Cancer Group Specialised Register (Up to October 2002). In addition we manually searched the reference lists of the primary identified trials.

SELECTION CRITERIA

We evaluated Randomised Controlled Trials (RCTs) and Controlled Clinical Trials (CCTs) in which any antibiotic regime were compared to placebo in patients suspected of having appendicitis, and undergoing appendectomy. Both studies on children and adults were reviewed. The outcome measures of the studies were: Wound infection, intra abdominal abscess, length of stay in hospital, and mortality.

DATA COLLECTION AND ANALYSIS

Eligibility and trial quality were assessed, recorded and cross-checked by two reviewers.

MAIN RESULTS

Forty-five studies including 9576 patients were included in this review. The overall result is that the use of antibiotics is superior to placebo for preventing wound infection and intraabdominal abscess, with no apparent difference in the nature of the removed appendix. Studies exclusively on children and studies examining topical application reported results in favour to the above although the results were not significant.

REVIEWER'S CONCLUSIONS

Antibiotic prophylaxis is effective in the prevention of postoperative complications in appendectomised patients, whether the administration is given pre-, peri- or post-operatively, and could be considered for routine in emergency appendectomies.

Molecular evolution of puumala hantavirus in Fennoscandia: phylogenetic analysis of strains from two recolonization routes, Karelia and Denmark

Like other members of the genus HANTAVIRUS: in the family BUNYAVIRIDAE:, Puumala virus (PUUV) is thought to be co-evolving with its natural host, the bank vole Clethrionomys glareolus. To gain insight into the evolutionary history of PUUV in northern Europe during the last post-glacial period, we have studied wild-type PUUV strains originating from areas along two postulated immigration routes of bank voles to Fennoscandia. Full-length sequences of the S RNA segment and partial sequences (nt 2168-2569) of the M segment were recovered by RT-PCR directly from bank vole tissues collected at three locations in Russian Karelia and one location in Denmark. Phylogenetic analysis showed that strains from Karelia and Finland belong to the same genetic lineage, supporting the hypothesis that PUUV spread to present Finland via a Karelian land-bridge. The Danish PUUV strains showed no particularly close relatedness to any of the known PUUV strains and formed a distinct phylogenetic lineage on trees calculated for both S and M segment sequences. Although no direct link between the Danish PUUV strains and those of the southern Scandinavian lineage was found, within the S segment of Danish PUUV strains, two regions with higher similarity to either northern Scandinavian or - to a less extent - southern Scandinavian genetic lineages were revealed, suggesting evolutionary connections of their precursors.

[Suture foreign body reaction as a mammographic pitfall]

A mammographic pitfall is presented. After lumpectomy owing to cancer in the breast a woman developed an immediate allergic reaction presumably caused by the subcutaneous sutures (vicryl). After adjuvant irradiation the breast became swollen and mammography gave suspicion of a recurrent breast cancer. Surgical excision was performed and examination of the biopsy specimen showed a foreign body reaction to the suture material with fibrosis and eosinophilia.

Preventing acute rejection, Epstein-Barr virus infection, and posttransplant lymphoproliferative disorders after kidney transplantation: use of aciclovir and mycophenolate mofetil in a steroid-free immunosuppressive protocol

BACKGROUND

A widely held view is that any increase in the potency of an immunosuppressive agent will lead to an increase in infection and malignancy, such as life-threatening Epstein-Barr virus (EBV) induced posttransplant lymphoproliferative disorders (PTLD). We tested this paradigm by studying the effect of adding mofetil to a steroid-free protocol under cover of high-dose aciclovir prophylaxis on the number of acute rejections, EBV infections and PTLDs after kidney transplantation.

METHODS

EBV serology was performed in 267 consecutive renal transplantations (1990-1997). All were treated with cyclosporine with an initial 10-day antilymphocyte globulin course, supplemented from September 1995 with MMF. In 208 consecutive transplantations after June 1992 aciclovir 3200 mg/day was given for 3 months posttransplantation.

RESULTS

After an observation period of up to 7 years we found that: (1) primary or reactivated EBV infection (PREBV) was correlated to acute rejection (treated with OKT3; P<0.00005) and to the incidence of PTLD (P=0.03; P=0.01, if Hodgkin's disease is included); (2) aciclovir protected against PREBV (P<0.00005) and (3) adding mofetil to the immunosuppressive protocol reduced PREBV further (P=0.0001), (4) in 78 transplantations treated with cyclosporine/antilymphocyte globulin/mofetil we observed only 10 acute rejections (P=0.0001), 10 PREBVs (P<0.00005), and no PTLDs compared with the cyclosporine/antilymphocyte globulin group (P=0.04).

CONCLUSIONS

Supplemental immunosuppression with mofetil protects against acute rejection. In combination with aciclovir, there is also a reduction in the number of PREBVs, apparently as a result of both direct viral prophylaxis and better rejection control, and in the incidence of EBV-induced PTLD.

Interleukin-10 and posttransplant lymphoproliferative disorder after kidney transplantation

BACKGROUND

Posttransplant lymphoproliferative disorder (PTLD) is a life-threatening complication of transplantation, which comprises a morphologically and clinically heterogeneous spectrum of B-lymphocyte diseases. Risk factors include primary or reactivated Epstein-Barr virus (EBV) infection, and the type and duration of immunosuppression. Interleukin-10 (IL-10) is a pleiotropic cytokine, produced primarily by T-helper 2 (Th2) lymphocytes in the later stages of T-cell activation, suggested to play a role in EBV-associated PTLD. We recently reported preliminary findings on IL-10 in relation to the development of PTLD in three kidney transplanted patients. The study now includes nine patients that could be followed before and/or after the occurrence of lymphoma.

METHODS

Nine patients with lymphomas (eight PTLDs and one Hodgkin's disease) were diagnosed among 268 consecutive renal transplantations (1990-1997). All were treated with cyclosporine with an initial 10-day course of antilymphocyte globulin, supplemented from 1995 with mycophenolate mofetil. Serum antibodies against EBV were detected using recombinant antigens. A double sandwich enzyme-linked immunosorbent assay using rabbit antibodies to purified human recombinant IL-10 was employed; the assay is specific for human natural and viral IL-10.

RESULTS

Three patients experienced primary EBV infection, five reactivated EBV infections, and one did not change EBV status. Three patients had a fulminant course and died with EBV-associated PTLD confirmed post mortem. The other six are alive and are apparently cured. Treatment was immediate discontinuation of immunosuppression (in all PTLDs) and long-term high-dose aciclovir in all but one. Two patients have maintained excellent graft function for 3 and 2 years, respectively, without immunosuppression and are now in a state of operational tolerance. In three of four cases with initial lymphoma, EBV infection (primary or reactivation) preceded the increase in IL-10. In all four cases, the IL-10 increase preceded the PTLD diagnosis. In six cases, IL-10 could be followed after treatment showing either immediate zero or a decrease to zero.

CONCLUSION

IL-10 seems to play a role in EBV-associated PTLD. Moreover, IL-10 may have an important role in transplant tolerance by inducing long-lasting anergy to donor- and host-specific alloantigens, perhaps caused by down-regulation of Th1 cytokines in the graft. If substantiated, this may provide new insight into the pathogenesis of PTLD introducing new strategies for prevention and therapy of PTLD, and for the induction of tolerance in transplanted patients.

[Complications in two children with acute lymphatic leukemia caused by vaccination against varicella zoster virus]

Complications in two varicella zoster virus (VZV) vaccinated children with leukemia in remission are reported. Case I presented with varicella on day 30 after vaccination, with a relapse on day 49 and development of zoster on day 70. VZV was detected in vesicles by PCR on days 49 and 70. Case II presented with varicella on day 32 after vaccination, and VZV was detected in vesicles and nasal secretion. The manifestations were mild and responded to treatment. PCR methods were directed toward the R5 and PS regions. The virus from the two children was unambiguously identified as the Oka vaccine strain. The majority of Danish field strains had only one copy of the 112 basepair repeat element in the R5 region, but two, four and presumably higher copy numbers were also seen. All Danish field strains had the Pst1 cleavage site in the PS region.

Effect of steam sterilization inside the turbine chambers of dental turbines

OBJECTIVE

It has been demonstrated that contamination of the insides of high-speed dental turbines occurs and that bacteria as well as viruses may remain infectious when expelled from such turbines during subsequent use. Consequently, it has been widely recommended that a high-speed turbine be sterilized after each patient. The purpose of this study was to evaluate the effect of steam autoclaving on a high-speed dental turbine with a contaminated turbine chamber.

STUDY DESIGN

Streptococcus salivarius and endospores of Bacillus stearothermophilus were used as test organisms to determine the effectiveness of 4 different small non-vacuum autoclaves and one vacuum autoclave.

RESULTS

The study demonstrated different efficiencies among the small non-vacuum autoclaves, the best showing close to a 6 log reduction of the test organisms inside the turbine chamber. When cleaning and lubrication of the high-speed dental turbine was carried out before autoclaving, this level of reduction was observed for all the examined non-vacuum autoclaves.

CONCLUSIONS

It is concluded that cleaning before sterilization is essential for safe use of high-speed dental turbines and that small non-vacuum autoclaves should be carefully evaluated before being used for the reprocessing of hollow instruments such as high-speed turbines.

Prophylaxis against herpes infections in kidney transplant patients with special emphasis on CMV

METHOD

Since 1990, we have treated all kidney transplanted patients with cyclosporin (CsA)+ an initial 10 d antilymphocyte globulin (ALG) course, from September 1995 supplemented with mycophenolate mofetil (MMF). In 170 consecutive transplantations from June 1992 to the end of 1996, aciclovir 3200 mg/d (adjusted for kidney function and in children to age) was given prophylactically for 3 months post-transplantation (Tx), monitored with systematic and frequent tests for HSV and CMV. In case of CMV infection, we gave ganciclovir intravenously (oral ganciclovir from 1996) in doses according to kidney function for 3 months, followed by a further 3 months observation and monitoring period. In case of acute cellular rejection, ganciclovir was given during the 10-d OKT3 course and 1 week further. In case of delayed graft function combined with aciclovir side effects, ganciclovir was given until aciclovir could be reintroduced.

RESULTS

39% were HSV seronegative at Tx. There were no seroconversions or reactivations within the observation period. No mucocutaneous HSV infections was observed. No resistant strains developed. 26% were both HSV and CMV negative at Tx. 52% were CMV negative at Tx. 30% experienced a CMV infection post-transplant. The patients were grouped according to CMV status in the donor (D) and recipient (R) before Tx. We found approximately the same number of patients in the 4 CMV groups D-/R-, D+/R-, D-/R+ and D+/R+. Most infections occurred in the D+/R- group compared to D-/R- (p = 0.009). A significant increase in the number of CMV infections occurred in this subgroup when we gave reduced doses in case of delayed graft function (p = 0.015), from 1994. We observed only 1 CMV disease (in 1992). Serological EBV testing were performed concomitantly. No correlation was seen between CMV and EBV infections. From September 1995 we have treated all transplanted patients (n = 40) with CsA/ALG/MMF. We found no significant increase in CMV infections in this group.

CONCLUSIONS

Prophylaxis with aciclovir (combined with ganciclovir during acute rejections and in case of delayed graft function with aciclovir side effects) gives a good protection against HSV and CMV infections and prevents CMV disease effectively. High-dose aciclovir post-transplantation (or shift to ganciclovir) seems to be important to obtain effective prophylaxis. Better immunosuppression with MMF does not result in more CMV infections.

Evaluation of a new device for sterilizing dental high-speed handpieces

Dental high-speed turbines and handpieces can take up and expel microorganisms during operation and thus need regular sterilization. This study established a method for validating devices used to sterilize high-speed turbines and handpieces. The air and water channels and turbine chambers were contaminated with suspensions of Streptococcus salivarius or endospores of Bacillus stearothermophilus. The effect of flushing and/or autoclaving performed by a new device combining both procedures was evaluated by counting the number of viable bacteria recovered from these devices. Further, the effect on clinically used handpieces was evaluated. In an initial experiment, the device partially reduced S. salivarius, and the endospores survived. In a second experiment, a 5 to 6 log reduction of S. salivarius in air and water channels was obtained. No growth was observed in clinically used high-speed handpieces, and both S. salivarius and endospores were eliminated from the turbine chambers. Thus, the method of validation proved capable of discriminating between different levels of bacterial reduction.

Maxi K+ channels in the basolateral membrane of the exocrine frog skin gland regulated by intracellular calcium and pH

With the single-channel patch-clamp technique we have identified Ca2+-sensitive, high-conductance (maxi) K+ channels in the basolateral membrane (BLM) of exocrine gland cells in frog skin. Under resting conditions, maxi K+ channels were normally quiescent, but they were activated by muscarinic agonists or by high serosal K+. In excised inside-out patches and with symmetrical 140mmol/l K+, single-channel conductance was 200pS and the channel exhibited a high selectivity for K+ over Na+. Depolarization of the BLM increased maxi K+ channel activity. Increasing cytosolic free Ca2+ (by addition of 100nmol/l thapsigargin to the bathing solution of cell-attached patches also increased channel activity, whereas thapsigargin had no effect when added to excised inside-out patches. An increase in cytosolic free Ca2+ directly activated channel activity in a voltage-dependent manner. Maxi K+ channel activity was sensitive to changes in intracellular pH, with maximal activity at pH 7.4 and decreasing activities following acidification and alkalinization. Maxi K+ channel outward current was reversibly blocked by micromolar concentrations of Ba2+ from the cytosolic and extracellular site, and was irreversibly blocked by micromolar concentrations of charybdotoxin and kaliotoxin from the extracellular site in outside-out patches.

Evaluation of Abbott TestPack RSV and an in-house RSV ELISA for detection of respiratory syncytial virus in respiratory tract aspirates

The Abbott TestPack RSV was compared with an in-house RSV enzyme-linked immunosorbent assay (ELISA) for detection of respiratory syncytial virus (RSV) antigen. Nasopharyngeal specimens were obtained from 121 inpatients. RSV antigen was detected in 46 specimens by the Abbott TestPack, 42 of these being confirmed by the in-house RSV ELISA. Of the 75 specimens tested negative in the Abbott TestPack RSV, one was found positive by the in-house RSV ELISA. The sensitivity and specificity of the Abbott TestPack RSV versus the RSV ELISA were 98% and 95% respectively.

[Legionella pneumophila in the hot water system of Danish hospitals and institutions. A questionnaire study and a random sample test]

Hitherto, nosocomial epidemic outbreaks of legionnaire's disease have not been reported in Denmark. Only sporadic cases have been described. A survey of 75 Danish hospitals concerning the dimensions and operation of the hot-water systems revealed that only 13% had a hot water tank temperature above the recommended 60 degrees C. Temperatures of coldest tap water and of returning water were above 50 degrees C in only 31% and 24% respectively. Twelve representative hospitals with 35 independent water systems were investigated for the presence of Legionella pneumophila (Lp). Lp was demonstrated in all the hospitals and in 34 (97%) of the systems. The prevailing serogroups were (in order of frequency) 3, 1, 2, 5 and 6. We conclude that the operation of the hot tap water systems should be optimized. This report indicates that nosocomial epidemics are conceivable and attention should be paid to the disease as a diagnostic possibility in patients with primary atypical pneumonia.

Decontamination of dental equipment. A validation of three devices designed for cleaning, disinfecting, and lubricating of dental high-speed turbines and handpieces

This study deals with the decontamination of dental turbines and handpieces (DTH) aiming at eliminating the cross-infection risk in dental practice. Three types of equipment designed for cleaning/lubricating DTH were validated. The effect of the three devices was determined for four different types of DTH, which were artificially contaminated with Streptococcus salivarius ATCC 13419 in a controlled manner. Sampling was carried out by collecting one ml water flushed through the DTH connected to a dental unit. The study resulted in a model for testing the decontamination potential of a cleaning/lubrication device for DTH. One of the devices could not reduce the contamination, while two others were able to reduce the bioburden with at least 3.9 logarithmic steps. However none of the devices tested could constantly eliminate the contamination, for which reason an additional heat treatment of the DTH is recommended.

Bacteremia at a Danish university hospital during a twenty-five-year period (1968-1992)

In the 25-year period 1968-92, 3,317 out of 477,420 patients admitted to Frederiksberg Hospital experienced 3,491 episodes of bacteremia. Enterobacteriaceae dominated as causative agents (57%), following by Gram-positive cocci (31%) and anaerobes (7%). Polymicrobial bacteremia was found in 8% of the episodes. The incidence of Enterobacteriaceae bacteremia culminated in the middle (1978-82) of the period (4.7/1,000 admissions) and decreased during the last decade. Gram-positive bacteremia increased throughout the period (from 1.8 to 2.9; p < 0.001), due mainly to increasing incidences of bacteremia caused by non-hemolytic streptococci, Streptococcus pneumoniae and coagulase-negative staphylococci. Bacteroides fragilis accounted for a rising incidence of anaerobic bacteremia (from 0.3 to 0.7; p < 0.05). Clinical data were available for the 2,599 bacteremic episodes in the 20-year period 1968-87. 59% of these were hospital acquired. Of those, 38% were associated with indwelling catheters, mainly bladder catheters (28%) and i.v. lines (7%). The urinary tract dominated as source of bacteremia (46%), followed by the respiratory (11%) and the gastrointestinal tract (9%). Half of the patients had predisposing underlying diseases, most frequently malignancies (20%) and diabetes mellitus (7%). The mortality rate related to bacteremia decreased from 25% to 11% (p < 0.001). More than half (55%) of the fatal cases related to bacteremia occurred within the first 2 days after the first positive blood culture was obtained. Logistic regression analysis defined 7 variables that independently influenced the outcome related to bacteremia: age, source, culture verification of source, shock, body temperature, leukocyte count and empiric antibiotic treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

[Epidemiology of Legionnaires' disease in Denmark. A comparative study]

An epidemiological study of Legionnaires' disease in Denmark is presented. A high incidence of apparently sporadic cases of Legionnaires' disease in Denmark was found. The source of infection remains obscure in most cases. No outbreaks have been registered in Denmark, in contrast to most European countries. It is concluded that intensified surveillance, including monitoring of water distribution systems in hospitals, combined with an earlier etiological diagnosis might disclose more nosocomial cases.

Infective endocarditis with involvement of the tricuspid valve due to Capnocytophaga canimorsus

A case of endocarditis with vegetations on the tricuspid valve caused by Capnocytophaga canimorsus is described. Extensive diagnostic investigations preceded the diagnosis, including blood cultures, 34 of which were sterile. A possible role of the pulmonary circulation in the negative blood cultures is discussed.

[Vibrio vulnificus]

A patient sustained a knife wound while cleaning eels and subsequently severe wound infection developed. Vibrio vulnificus was isolated from the wound and, on the basis of this, the main features of the epidemiology of the bacteria and the typical clinical pictures are reviewed.

Haemorrhagic fever with renal syndrome: evaluation of ELISA for detection of Puumala-virus-specific IgG and IgM

IgM and IgG ELISA to Puumala virus were evaluated using sera from patients with haemorrhagic fever with renal syndrome (HFRS) from different geographical regions: Sweden, Denmark, Norway, Belgium and the European USSR. IgM ELISA proved useful in the diagnosis of HFRS in patients from all the regions mentioned above. Specific IgM could be detected as early as day 1 post onset of disease, and patients remained IgM-positive for several months. Specific IgG ELISA antibodies were also frequently detected in acute sera, and acute-convalescent serum pairs often failed to show a significant titre rise or increase in optical density (OD) values. This limits the use of IgG ELISA in patient diagnosis. Sera collected 2 years after infection revealed higher IgG ELISA OD readings than convalescent sera, and very high values were still detectable 10 to 20 years postinfection. IgG ELISA is therefore useful for the testing of immunity and in seroepidemiological studies. Acute and convalescent sera from HFRS patients in Korea and the Asian USSR showed no or only very weak reactivity in the Puumala virus IgG and IgM ELISA. These results are consistent with the "one-way" crossing described earlier.

[Nephropathia epidemica. Hantavirus and acute renal insufficiency]

Puumala virus belongs to the hantavirus group and as other members of the group it can cause acute renal insufficiency. Other hantaviruses are responsible for Korean hemorrhagic fever and other hemorrhagic fevers with renal involvement. In Scandinavia, hantavirus nephropathy is better known as nephropathia epidemica. Hantavirus cause asymptomatic infections in mice and rats and the virus is thought to be transmitted to man via inhalation of desicated saliva, urine or feces from infected animals. In the other Nordic countries, the bank vole (Clethrionomys glareolus) is the commonest natural host. Laboratory infections from rats have been reported from all over the world. The disease presents with fever, back and/or abdominal pain, acute renal insufficiency and a bleeding tendency. The latter is usual less pronounced in the European than in the Asian forms of hantavirus infection. The disease is commoner in men and is endemic in forested areas. The greatest incidence is seen in those years when the numbers of mice are greatest. The mortality in nephropathia epidemica appears to be less than 0.5% in contrast to a mortality of about 10% in Korean hemorrhagic fever. Diagnosis is made by demonstration of a significant increase in antibody titer to hantavirus. Treatment is symptomatic and consists primarily of restitution of fluid and electrolyte balance, at times with dialysis. After recovery from hantavirus infection renal function returns to normal. The incidence and prevalence of nephropathia epidemica in Denmark are unknown. The first two cases of Puumala virus infection in Denmark are reported.

Specific serum immunoglobulin D, detected by antibody capture enzyme-linked immunosorbent assay (ELISA), in cytomegalovirus infection

An antibody capture enzyme-linked immunosorbent assay (ELISA) was developed for the detection of immunoglobulin D (IgD) antibodies to cytomegalovirus (CMV) in sera from blood donors and various groups of patients infected with CMV. This method has previously been found especially valuable in detecting specific antibodies of the IgM, IgE, IgA and IgG class in patients with CMV infection. Specific CMV IgD antibodies were found in 37% of CMV seropositive blood donors and in 47 (88%) of the 53 patients investigated, including bone marrow transplant and renal allograft transplant patients, patients with CMV mononucleosis, neonates with CMV infection and AIDS patients with CMV infection. The highest IgD reactivity was found in patients having either a primary post-transplant CMV infection or CMV mononucleosis. The IgD reactivity in patients with AIDS and in neonates was low. It was also found that in the acute phase of CMV infection the development of CMV antibodies of the IgD class was similar to the development of antibodies of the other classes. The maintenance of IgD activity in some patients together with the presence of CMV IgD antibodies in a great proportion of the blood donors indicates that the development of CMV IgD antibodies resembles that of the IgG class. Determination of specific IgD antibodies offered no advantage over determination of specific antibodies of the IgM, IgE and IgA classes in the diagnosis of CMV infection.

Kinetics of specific immunoglobulins M, E, A, and G in congenital, primary, and secondary cytomegalovirus infection studied by antibody-capture enzyme-linked immunosorbent assay

Antibody-capture enzyme-linked immunosorbent assay (ELISA) using enzyme-labeled cytomegalovirus (CMV) nuclear antigen is a reliable and easily performed test suitable for routine use. As the serologic response to CMV infection may, however, vary considerably among patients, we have studied the kinetics of CMV-specific immunoglobulin M (IgM), IgE, IgA, and IgG antibodies in 352 sera from 61 patients by using antibody-capture ELISA and complement fixation (CF) tests. In a CMV mononucleosis group (n = 17), most patients had antibodies of all four immunoglobulin classes, but antibody levels decreased rapidly, with half the patients having a borderline-positive or a negative reaction for all classes, except IgG, 2 months after the appearance of symptoms. Twelve patients with a primary CMV infection after renal or bone marrow transplantation also developed all immunoglobulin-class antibodies. In only two patients did CMV IgM and IgE antibodies precede seroconversion of CF antibodies, and in one patient, these antibodies lagged months behind. Most patients had all classes of CMV antibodies, except IgA, for a year or more. Among 10 transplant patients with a secondary CMV infection, 50% had long-lasting IgM antibodies, and very few had IgE or IgA antibodies, but all had IgG antibodies to CMV. In 13 infected infants, the CMV-specific serologic response was also characterized by long-lasting IgM, IgE, and IgG antibodies. Two patients did not develop detectable IgM antibodies, and one of these did not show IgE antibodies either. The IgA response in infants as a whole was lacking; a few, however, were borderline positive. Of the nine acquired immunodeficiency syndrome patients with CMV infection studied during their last year of life, only one had antibodies in all four classes, the rest had only CF antibodies, and all except for one had IgG-class antibodies. All sera studied were also tested against a control antigen produced from noninfected cell nuclei. It was found that some patients developed antibodies to nuclear antigens in parallel with the rise in specific antibodies. The nonspecific antibodies occurred in all four classes, but most often they were of the IgM class. Addition of unlabeled control antigen to the conjugates was not always sufficient to abort this nonspecific reaction.

High levels of complement fixing antibodies against cytomegalovirus in patients with primary Sjögren's syndrome

Antibodies to cytomegalovirus (CMV) were examined in sera from 21 consecutive patients with primary Sjögren's syndrome (SS) and 19 consecutive patients with secondary SS, using a complement fixation (CF) test and an antibody capture enzyme-linked immunosorbent assay (ELISA). Sera from 15 CMV-negative subjects, 15 CMV-positive subjects, 3 patients with primary CMV infection and 3 patients with recurrent CMV infection served as controls. The prevalence of CMV antibodies in the patients with primary and secondary SS was found similar to the prevalence known to occur in the normal adult population. Unrelated to clinical parameters, 5 patients with primary SS (24%) had high levels of CF antibodies against CMV. Ig class antibodies to CMV were not elevated in these 5 patients. Preferential production of CF antibodies to CMV may be a pathogenetic factor in some patients with primary SS.

Improvement of serological diagnosis of neonatal cytomegalovirus infection by simultaneously testing for specific immunoglobulins E and M by antibody-capture enzyme-linked immunosorbent assay

This study describes the results of testing 92 serum samples, including 10 umbilical cord serum samples, from 38 cytomegalovirus (CMV)-infected neonates for CMV-specific immunoglobulins E (IgE) and M by antibody-capture enzyme-linked immunosorbent assays with enzyme-labeled CMV antigen. All infants excreted CMV in the urine. It was demonstrated that the CMV IgE test was more sensitive than the CMV IgM test in diagnosing CMV infection in neonates by serology. Thus, the sensitivity for the IgE test was 82%, whereas for the IgM test it was only 66%. Furthermore, the CMV-specific IgE response, expressed as absorbance, was higher than the specific IgM response in 91% of the 76 sera which contained antibodies of either one or both immunoglobulin classes. Forty-six control sera, including 18 umbilical cord sera, from 46 neonates from whom CMV was not isolated were also tested. Most sera were negative. Three infants, however, had CMV antibodies of one or both classes, indicating infection. The level of total serum IgE was controlled in 24 of the sera from the CMV-infected neonates, but in none of the cases was the level elevated. No correlation was found between the reactivity of the antibodies in the two immunoglobulin classes and the level of CMV in urine.

A prospective study on infection with cytomegalovirus in renal allograft recipients immunosuppressed with cyclosporine A and low dose prednisone

To investigate the course of infection with cytomegalovirus (CMV) in renal allograft recipients treated with cyclosporine A, 10 patients were followed for 1 year after transplantation. Virus cultures from blood, urine and throat washings were performed employing a quantitative technique. Complement-fixing and IgM antibodies to CMV were measured at scheduled intervals. The incidence 90% and course of CMV infections were found not to differ from those reported in patients receiving conventional immunosuppressive therapy. The quantitative virus cultures showed a consistent pattern with viremia most prominent at the beginning of an infection, and the highest concentration found in the one patient who developed symptoms of viral disease. It is suggested that information about the concentration of virus in a specimen will improve the diagnostic value of virus cultures in this group of patients.

Detection of immunoglobulin G antibodies to cytomegalovirus antigens by antibody capture enzyme-linked immunosorbent assay

An antibody capture enzyme-linked immunosorbent assay (ELISA) that uses horseradish-peroxidase-labeled antigen for the detection of immunoglobulin G (IgG) antibodies to cytomegalovirus (CMV) is described. A microtiter plate was coated with anti-human IgG and consecutively incubated with serum specimens, enzyme-labeled CMV antigen made from CMV-infected cell nuclei, and substrate. The CMV IgG antibody content was determined spectrophotometrically and expressed as absorbance. Furthermore, to reveal any nonspecific reactions, all sera were tested against an enzyme-labeled control antigen made from uninfected cell nuclei. The problem with nonspecific reactions was small and was circumvented by the addition of unlabeled control antigen to the conjugates. For epidemiological studies the test was not as sensitive as other serological tests. On the other hand, the IgG antibody capture ELISA was highly sensitive for detecting the serological antibody response in patients with primary and recurrent CMV infections. Thus, one positive serum remained positive at a serum dilution of 1:10(7). The specificity of the test was shown by a blocking experiment and by testing 126 complement fixation-positive sera, of which 97% were positive. There was a rather good correlation between the complement fixation test and the IgG antibody capture ELISA (rs = 0.79, P less than 0.001). The test is especially useful when tests for CMV antibodies of the IgM, IgA, and IgE classes are run by similar antibody capture ELISAs, since the same procedure and conjugate are used.

Correlation between donor cytomegalovirus immunity and chronic graft-versus-host disease after allogeneic bone marrow transplantation

Chronic graft-versus-host disease (GvHD) in bone marrow allograft recipients is frequently preceded by a cytomegalovirus (CMV) infection. To elucidate whether an immune reaction of transplanted donor cells against CMV was involved in the pathogenesis of chronic GvHD, the effect of donor pretransplant CMV immune status on chronic GvHD incidence was analyzed. In 43 bone marrow recipients at risk, the 2-yr cumulative chronic GvHD probability was 55% when the donor was immune, in contrast to 16.5% when the donor was non-immune (p less than 0.002). No correlation between recipient pretransplant CMV immunity and chronic GvHD was observed. Donor CMV immunity did not correlate with acute GvHD or posttranplant CMV infection and seemed to predispose for chronic GvHD regardless of donor and recipient age. However, the proportion of CMV immune donors increased with increasing donor and recipient age. This may account for the higher incidence of chronic GvHD in older patients. The present study suggests that chronic GvHD may be mediated by a reaction of immune donor cells against CMV infected recipient cells.

Cytomegalovirus infection after bone marrow transplantation: relation of pneumonia to postgrafting immunosuppressive treatment

Five fatal cases of CMV associated interstitial pneumonia occurred among 20 patients who had received allogenic bone marrow transplantation for acute leukemia or aplastic anaemia. This outcome was analysed in relation to prospectively obtained data on complement fixing (CF) and IgM anti-CMV titres and excretion of CMV in urine or pharynx. Altogether 16 patients had primary or reactivated CMV infection. Five of these patients receiving corticosteroids at the time of infection, at a dose of more than 1 mg/kg/day, failed to mount a significant CF antibody response, excreted large amounts of virus, and died from pneumonia, while the remaining 11 infected patients obtained high CF antibody titres and showed no severe symptoms related to CMV infection. IgM antibodies occurred simultaneously with CF antibodies in most cases of primary and reactivated infection. The results of the study suggest a protective role of the humoral immune response to CMV infection in BMT recipients, and passive immunisation with CMV hyperimmune globulin should be attempted especially in patients given additional immunosuppression with high dose corticosteroids.

Lifestyle and antiviral antibody studies among homosexual men in Denmark

Two-hundred and fifty-nine male homosexuals (HS) of a large and a small Danish town were studied for antibodies to various virus and their statistical relationship to sex habits, drug use and other lifestyle factors. Prevalence rates against cytomegalovirus (CMV) were 86.7% of HS men from Copenhagen and 73.3% of HS men from the smaller community of Aarhus, against 30% of a control group. Antibody prevalence in homosexuals was significantly related to number of years of homosexual activity (p less than 0.0001), number of partners (p less than 0.01), nitrite inhalant use in the past year (p less than 0.01), and independently to venereal disease during the past year (p less than 0.01). Titer levels correlated with number of years of HS activity (p less than 0.001), number of partners (p less than 0.01), and independently with nitrite use in the past year (p less than 0.01). The association between lifestyle and antibodies was not detectable for VCA-IgG, VCA-IgA, VCA-IgM, and EA antibodies to Epstein-Barr virus (EBV) or for antibodies to herpes simplex virus type 1 and type 2, parvovirus and rotavirus. In a subset of 78 HS men, T-helper/T-suppressor ratio was determined. No correlation was found between level of ratio and either prevalence or titer of antibodies against CMV, EBV-components or herpes type 1 and 2.

Danish children in Greenland have high Epstein-Barr virus titers

Danish children brought to Greenland have somewhat higher mean titers of antibodies to Epstein-Barr virus than do Danish children in Denmark, although their titers are lower than those found in Eskimo children. This study presents the first evidence of increases in Epstein-Barr virus titers in migrant children.

Seminal fluid excretion of cytomegalovirus related to immunosuppression in homosexual men

Seminal fluid samples from 84 Danish homosexual men were successfully cultured to determine the prevalence of cytomegalovirus excretion. Ten (15%) out of 66 men positive for the antibody were found to be excreting the virus. Although the proportion excreting was inversely related to age (p less than 0.01), three men aged over 30 and with many years of homosexual experience excreted the virus. In addition, a 50 year old man with Kaposi's sarcoma excreted the virus. A further study of the ratio of T cell helpers to suppressors in the men aged over 30 and a series of age matched non-excreting homosexual control or heterosexual men showed that those excreting cytomegalovirus in their seminal fluid had statistically lower ratios (all less than 0.77) than the controls (p less than 0.05). Excretion of cytomegalovirus may be related to re-emergence of latent infection in immunosuppressed homosexual men.

Rate of inactivation of cytomegalovirus in raw banked milk during storage at -20 degrees C and pasteurisation

Samples of milk from 23 mothers attending the department of obstetrics and gynaecology and 36 who donated milk to the department's milk bank were cultured for cytomegalovirus. Virus was isolated from samples from 12 of the milk donors but none of the mothers attending the department; follow-up studies during lactation in seven of these 12 women showed that five continued to excrete the virus. Samples were taken on three occasions from one woman who regularly excreted high titres of the virus. Storage at -20 degrees C for over three days reduced the titre by over 99%; after pasteurisation at 63 degrees C for eight minutes the milk did not contain any viable virus. It is recommended that raw banked milk used for feeding preterm babies should be kept frozen for at least 72 hours before feeding.

Cytomegalovirus antibodies in epileptics receiving diphenylhydantoin

Cytomegalovirus (CMV) antibodies were determined by indirect haemagglutination in 53 epileptics receiving long-term diphenylhydantoin (DPH) therapy and in 53 matched controls. Absorption of serum IgG, IgA and IgM performed in 12 sera showed that the antibodies were of the IgG class. A decreased incidence of high CMV antibody titres (greater than or equal to 320) was found in epileptics (11.3%) compared with controls (34.0%) (0.02 greater than P greater than 0.01), whereas antibody titres greater than or equal to 40 were found in 37.7% of epileptics and in 45.3% of controls (n.s.). The CMV antibody incidence and titre range were similar in patients with symptomatic (37.9%) and idiopathic (37.5%) epilepsy, suggesting that the DPH treatment was responsible for the decreased antibody occurrence in patients. No correlation between CMV antibody titres and the serum immunoglobulin levels or the DPH concentration or clearance could be established in the epileptics.

Antibodies to pigeon antigens in pigeon breeders. Detection of antibodies by an enzyme-linked immunosorbent assay

Antibodies to whole pigeon serum (PS) and pigeon dropping extract (PDE) were investigated in pigeon breeders and controls by an enzyme-linked immunosorbent assay (ELISA). The optimal antigen concentration was in the range of 3-30 microgram protein/ml for both PS and PDE. PDE antibody titres greater than or equal to 10240 were found in three (75%) of four patients with pigeon breeders' disease (PBD) and in 19 (13.6%) of 140 other pigeon breeders (P = 0.011). PS antibody titres greater than or equal to 10240 occurred in all four (100%) PBD patients and in only seven (5.0%) of 140 other breeders (P = 0.0002). In 85 blood donors antibodies in low titres against PS and PDE occurred in 4.7% and 7.1%, respectively. By immunodiffusion three or more precipitin lines were found more often in PBD patients than in other breeders (P = 0.0006), and the highest ELISA antibody titres occurred in patients with precipitating antibodies. No correlation between P blood group phenotypes or anti-P1 antibodies and respiratory symptoms or antibodies to pigeon antigens could be demonstrated.

Recovery of mice from herpes simplex virus type 2 hepatitis: adoptive transfer of recovery with immune spleen cells

Young BALB/c mice inoculated intraperitoneally with herpes simplex virus type 2 develop focal necrotizing hepatitis. After infection, the livers of these mice show increasing virus titers, which reach a maximum on day 3 after infection; this is followed by a dramatic decrease in the amount of virus recovered on days 4 and 5. This decrease in virus content is accompanied by a progressive infiltration of the lesions with mononuclear leukocytes and an apparent resolution of the lesions. Adoptive transfer of immune spleen cells from mice infected 6 days earlier accelerated this process. When 50 x 10(6) to 100 x 10(6) immune spleen cells were transferred 24 h after infection, the inflammatory response and the clearance of virus from the livers were advanced by almost 2 days. As few as 12 x 10(6) immune spleen cells accelerated the healing process, whereas fewer immune cells, disrupted immune cells, or normal spleen cells did not have an effect. The protection conferred by herpes simplex virus type 2-sensitized immune spleen cells was specific since mouse cytomegalovirus- or vaccinia virus-sensitized immune spleen cells had no effect on the course of infection with herpes simplex virus type 2, whereas some cross-reactivity was observed between herpes simplex virus types 1 and 2. This model seems to be suitable for examining the immunological mechanisms that are active during recovery from visceral herpes simplex virus infections.

Enzyme linked immunosorbent assay (ELISA) for determination of IgG antibodies to human cytomegalovirus

A solid-phase enzyme linked immunosorbent assay (ELISA) for determination of IgG antibodies to cytomegalovirus (CMV) is described. The assay used purified CMV and extracts of CMV infected cells as antigen. Antigens were desiccated onto the bottom surface of polystyrene microcuvettes. The antibodies bound to the antigens were assayed by anti-IgG-alkaline phosphate conjugate followed by addition of the enzyme substrate. Titration curves have been obtained from the sera of 35 blood donors and of 23 patients. Comparison of results obtained by ELISA with those obtained by complement fixation (CF) shows that there is agreement between the tests. Both purified CMV and extracts of CMV infected cells were found to be suitable antigens. Purified CMV was of value particularly in those sera which show high reactivity against control antigen. The ELISA technique described is approximately 412 to 548 times more sensitive than the CF test when purified CMV or extracts of CMV infected cells, respectively, are used as antigens. No significant heterotypic rise to CMV was observed by ELISA in three sets of sera with seroconversion to herpes simplex virus. The ELISA technique gives objective results, is easily performed, and may be adaptable as a routine test both for serological diagnosis of CMV infection and for screening of the general population.

Viral infections in renal allograft recipients treated with long-term immunosuppression

Thirty-nine renal allograft recipients who had received continuous immunosuppression for six to 13 years were examined clinically and virologically for evidence of past or present viral infection. Twenty-five had common warts, usually on the hands. In most the warts had appeared about one year after transplantation; once present, they never disappeared. Six patients had had a zoster rash from two months to four years after transplantation. None had had jaundice, and there was no change in the frequency of colds or non-specific fibrile illness. Four patients had no cytomegalovirus complement-fixing antibodies throughout the observation period; in the other 35 the antibody titre had risen appreciably during the first three to four months after transplantation. Antibody titres were high (mean 64) at follow-up, being only slightly lower than the highest titres achieved during the immediate postoperative period. None of the patients had had symptomatic cytomegalovirus infection, and in only two was the virus isolated from the urine at follow-up; the titres were extremely low. No changes occurred in the frequency of herpes simplex eruptions. Although all patients had herpes simplex humoral antibody, none excreted the virus. Although cytomegalovirus antibody titres were high, virus excretion was rare, indicating that chronic cytomegalovirus infection in these patients is immunologically well controlled.

Cell-mediated and humoral immune responses to herpes simplex virus and cytomegalovirus in renal transplant patients

Cell-mediated immunity to herpes simplex virus and cytomegalovirus, using the lymphocyte transformation test and interferon induction in lymphocytes, was studied in 59 patients from 1 day to 7 years after allotransplantation and compared with the results in normal subjects. Both parameters were permanently depressed with regard to cytomegalovirus. With herpes simplex virus, interferon production was also permanently depressed, whereas the transformation reaction was normal during the first year after transplantation and only slightly depressed in patients more than 1 year after transplantation. In 6 patients the above-mentioned assays and the complement fixation reaction were performed serially and related to the clinical signs of herpes simplex virus and cytomegalovirus infection. The relationship between depression of the transformation reaction and interferon production in lymphocytes and the occurrence of clinically evident herpes simplex virus and cytomegalovirus infections was, however, equivocal. The humoral immune response to herpes simplex virus was measured by the complement fixation test and the more sensitive antibody-dependent, cell-mediated cytotoxicity reaction, and a good correlation was found between these two tests, although only a few persons were found to be negative in the antibody-dependent, cell-mediated cytotoxicity reaction. The suggestion is made that only a few adults are "true" herpes simplex virus seronegative.

Reactivity of smooth-muscle antibodies with F- and G-actin

The reactivity of human smooth-muscle antibodies (SMA) with F- and G-actin was investigated by means of an enzyme-linked immunosorbent assay (ELISA). Polystyrene tubes were coated with F-actin, G-actin and tropomyosin. The optimal reactivity of SMA with F-actin was achieved with tubes coated with actin concentrations in the range of 10-100 mug/ml, while both lower and higher amounts yielded lower reactivity. The reactivity with G-actin was low and only a little higher than the reactivity with tropomyosin or uncoated tubes, but much lower than the reactivity with F-actin. The differences in reactivity of SMA with F- and G-actin could not be explained by differences in binding of the two forms of actin to the tubes, although 1.7-2.5 times more F-actin than G-actin bound to the polystyrene surface after coating with equivalent amounts of protein. SMA-negative sera did not react with F-actin coated tubes indicating that the binding of antibody was not due to non-immunological binding of immunoglobulins. Human SMA thus react better with F- than with G-actin.

A prospective study on the incidence and significance of congenital cytomegalovirus infection

Screening of 3060 neonates for congenital cytomegalovirus (CMV) infection by virus excretion in the urine showed an overall incidence of 0.4%. The incidence was about 1% for mothers between 16 and 25 years and only 0.2% for mothers between 25 and 35. No mothers over 35 years of age gave birth to congenitally infected infants. The percentage of women in the child-bearing age susceptible to CMV infection was estimated by the absence of CMV complement-fixing antibodies in cord sera and ranged from 48% to 33% with increasing age. None of the infected infants showed obvious signs of congenital CMV infection at birth. At follow-up, two infants showed slight, but transient symptoms compatible with a foetal infection; a pair of premature twins exhibited retarded physical and psychomotor development, but this could just as well be ascribed to the prematurity itself. None of the infants had detectable CMV--IgM antibodies in cord sera, but a trend towards elevated total IgM concentration in cord sera and elevated virus excretion titres appeared in the infants with symptoms. With the very low incidence and no signs of sensomotor sequelae the preliminary conclusion is that foetal CMV infection in our population by no means has a significance to deserve screening or a vaccination programme.

Stimulation of human lymphocytes by cytomegalovirions and dense bodies

Lymphocytes from healthy adult individuals were examined for their ability to incorporate thymidine in the presence of cytomegalovirus (CMV) and dense bodies. It was found that lymphocytes from donors with antibodies to CMV were stimulated to incorporate thymidine-14C both by preparation of CMV and CMV dense bodies. Lymphocytes from CMV seronegative donors did not respond. Dilution experiments and the dose-response curve indicate that the stimulation induced by the dense body preparation was not caused by the small amounts of contaminating CMV particles. These results indicate that in healthy human adults there is a correlation between CMV seropositivity and in vitro lymphocyte transformation, induced by either CMV or by dense bodies.

Immunoglobulin levels and specific viral antibodies in relation to smooth-muscle antibodies in cytomegalovirus infection

Among 17 patients with cytomegalovirus (CMV) infection smooth-muscle antibodies (SMA) of the IgM class were detected in 9 (53%) and IgG-SMA in 6 (35%), while no IgA-SMA were found. IgM-SMA were present most often and in the highest titres (10-160) in the beginning of the disease, while IgG-SMA were found both early and late during the course of infection. SMA occurred most frequently in patients with specific CMV antibodies of the IgM class and in patients with elevated serum alanine aminotransferase values, but these relationships were not significant. Elevated levels of serum IgG, IgA and IgM were found in CMV infection, and a correlation between serum IgM values and IgM-SMA titres was demonstrated (alpha less than 0.01). A similar correlation between serum IgG and IgG-SMA could not be established. These findings are in support of the assumption that IgM-SMA account for a minor part of the elevated serum IgM levels in CMV infection, but not of the hypothesis that the stimulus for antibody production is the release of antigens from liver cells.