Implantable cardioverter defibrillator during laser transurethral resection of the prostate.

  Implantable cardioverter defibrillators have been instrumental in the health and safety of patients who are at increased risk of sudden death by ventricular tachycardia or fibrillation. Consensus on the perioperative management of cardiovascular implantable electronic devices has suggested that certain surgical interventions (including transurethral resection of the prostate) may interfere with the sensing capability of the device, thereby resulting in unforeseen adverse outcomes. However, improvements in the implantable cardioverter defibrillators have made it less susceptible to surgical interference. In addition, current guidelines recommend deactivation of the implantable cardioverter defibrillators to an asynchronous mode prior to most surgical interventions. We present the first two case reports in which implantable cardioverter defibrillators were not deactivated prior to GreenLight 180-W XPS laser-guided transurethral resection of the prostate. We left the implantable cardioverter defibrillators activated to allow them to detect and treat lethal arrhythmias by direct rather than extrinsic cardioversion. There was no cardiac arrhythmia incident in these two cases. Laser technology is not a documented source of electromagnetic interference in patients with implantable cardioverter defibrillators. There is no current evidence that links lasers to implantable cardioverter defibrillators malfunction. With increasing numbers of patients with implantable cardioverter defibrillators undergoing many different laser surgical procedures, further studies are warranted to analyze in depth the effects of laser therapy on implantable cardioverter defibrillators function and update in current guidelines.

Comparison of plaque reduction neutralisation test (PRNT) and measles virus-specific IgG ELISA for assessing immunogenicity of measles vaccination.

BACKGROUND: Plaque reduction neutralisation test (PRNT) is a gold standard assay for measles antibodies. PRNT, however, is time-consuming and more difficult to standardise than ELISA. METHODS: PRNT results were obtained on pre- and post-vaccination sera from 501 measles-vaccinated infants. From this cohort a sub-set of 210 infants were selected for testing by ELISA, which was performed either manually or by an automated processor. Results were corrected for sampling proportion before comparing the assays. RESULTS: Seroconversion was detected by PRNT in 454 infants of whom 324 were estimated to have seroconverted by manual ELISA and 191 by automated ELISA It is recommended that ELISA negative post-vaccination samples are re-tested by PRNT to detect all seroconversions.

Laboratory methods for assessing vaccine potency retained in aerosol outputs from nebulizers: application to World Health Organization measles aerosol project.

BACKGROUND: Laboratory methods for measuring vaccine potency of nebulized aerosol are required to support clinical trials of measles aerosol vaccination. METHODS: Measles vaccine containing the Edmonston Zagreb virus strain was reconstituted in sodium fluoride as tracer and nebulized from three devices. Emitted aerosol was collected using an impinger. Aliquots were removed from the impinger chamber for vaccine virus plaque assay and for fluoride measurement to determine aerosol output. RESULTS: Vaccine potency retention results were adjusted to take into account the effect of aerosol output on estimates. Adjusted potency of nebulized vaccine ranged from 88% to 102%. CONCLUSIONS: New laboratory methods to measure aerosol vaccine potency retention were reliable and accurate. The results demonstrated that Edmonston Zagreb vaccine remains robust during aerosolisation and imply that this is a viable candidate for further evaluation in the measles aerosol project.

Balancing urgency, age and quality of life in organ allocation decisions--what would you do? A survey.

PURPOSE: Explore public attitudes towards the trade-offs between justice and medical outcome inherent in organ allocation decisions. BACKGROUND: The US Task Force on Organ Transplantation recommended that considerations of justice, autonomy and medical outcome be part of all organ allocation decisions. Justice in this context may be modeled as a function of three types of need, related to age, clinical urgency, and quality of life. METHODS: A web-based survey was conducted in which respondents were asked to choose between two hypothetical patients who differed in clinical urgency (time to death <1 year), age, pretransplant and post-transplant quality of life, and life expectancy. RESULTS: A pool of 1600 people were notified via email about the survey; 623 (39%) responded. Respondents preferred giving organs to younger people up to an age difference of <15.4 years (SD 18) and more clinically urgent people up to a difference in urgency of <2.54 months (SD 3). Priority varied with the quality of life of the worst-off patient and the relative status of the patients. If both had worse than average quality of life, respondents preferred the better-off patient. When both had better than average quality of life, they preferred the worse-off patient. In analysis according to age versus clinical urgency, the older the patient, the more urgency needed to receive priority. In quality of life versus clinical urgency, the better the control's quality of life, the more urgency the competing patient required. The worse the patient's post-transplant outcome, the more urgency needed to receive priority. CONCLUSIONS: It appears that clinical urgency is only one of many factors influencing attitudes about allocation decisions and that respondents may invoke different principles of fairness depending the relative clinical status of patients.

Genetic variants of parvovirus B19 identified in the United Kingdom: implications for diagnostic testing.

BACKGROUND: Discrepant results in diagnostic parvovirus B19 PCR assays have been observed with strains showing nucleotide sequence variation. OBJECTIVES AND STUDY DESIGN: To perform phylogenetic analysis on two parvovirus B19 strains that gave discrepant PCR results. RESULTS: One strain was found to be genotype 2; the second strain was genotype 3. CONCLUSIONS: Parvovirus B19 genotypes 2 and 3 strains were identified in diagnostic samples of UK origin following the investigation of discrepant PCR results. More structured investigations are needed to estimate the prevalence of these variants. In the meantime, diagnostic PCR results should be interpreted cautiously when they are at variance with serological testing. Manufacturers of PCR kits for the detection of B19 sequences will need to consider re-designing their primers.

Measles immunity testing: comparison of two measles IgG ELISAs with plaque reduction neutralisation assay.

Two commercial IgG ELISAs, one based on recombinant nucleocapsid antigen and one based on cell culture grown native virus antigens, were evaluated for measles immunity testing by comparison with plaque reduction neutralisation test (PRNT). Qualitative results of the two ELISAs showed 92% agreement with those of PRNT. The sensitivity of the two ELISAs was 89.6%. False negative ELISA results were obtained in 10% of sera, mainly sera containing low levels of neutralising antibody. The specificity of both ELISAs was 100%. Measles IgG ELISAs perform adequately for immunity testing, correctly identifying seronegative individuals for vaccination.

Validation of a modified commercial assay for the detection of rubella-specific IgG in oral fluid for use in population studies.

Matching serum and oral fluid (saliva) samples were collected from 369 subjects in Tunisia in 2002, from a city in the north and a rural district in the south. Rubella-specific IgG was detected in sera by commercial ELISA (Dade Behring) and in matching oral fluids by two methods, a previously described IgG-capture ELISA (GACELISA) [J. Clin. Microbiol. 37 (1999) 391] and the Dade Behring ELISA with the assay protocol modified for use with oral fluids. Total IgG concentration of oral fluids was also measured. Rubella-specific IgG was detected in 289 (78.3%) sera overall. Differences in the age distribution of the study population in the north and south led to a higher prevalence being found in the north (86.2%) than in the south (71.8%). This difference was reflected in the oral fluid rubella-specific IgG results. With GACELISA, rubella-specific IgG was detected in 79.4% of oral fluids from the north and 69.7% from the south and with the modified Dade Behring assay, in 81.4% of oral fluids from the north and in 64.9% from the south. The sensitivity and specificity of GACELISA in comparison to results from the matching sera were 92.4 and 93.2%, respectively. The sensitivity and specificity of the modified Dade Behring ELISA were 89.8 and 92.0%, respectively. Total IgG concentration in oral fluid showed a weak correlation (r=0.19) with the modified Dade Behring results and with samples where total IgG was >7.5 mg/l, the sensitivity and specificity were 94.4 and 90.0%, respectively. Twenty-nine oral fluids, which gave false negative rubella-specific IgG results with the modified Dade Behring ELISA, had a lower mean total IgG concentration than 256 oral fluids which gave concordant positive results (7.0mg/l versus 15.8 mg/l, P<0.001). The study validated the modified Dade Behring ELISA, providing an alternative to the GACELISA for assessing levels of rubella immunity for population studies using oral fluid samples.

Use of RT-PCR on oral fluid samples to assist the identification of measles cases during an outbreak.

This study investigated the occurrence of mild modified measles cases during an outbreak in Niterói, RJ, Brazil by using RT-PCR on oral fluid samples. From August to December 1997 a total of 76 patients with rash were seen at the study sites. Confirmed diagnosis by serology was achieved in 47 cases: measles (39.5%), rubella (13.2%), HHV-6 (3.9%), human parvovirus B19 (3.9%), dengue fever (3%). For 19 of the 29 patients without a conclusive diagnosis paired serum and saliva samples were available for further tests. In four of them, measles virus RNA was detected by RT-PCR in saliva samples in the absence of specific IgM in serum samples. Vaccination histories obtained from three of the RT-PCR positive cases showed that individuals previously immunized can still be infected and contribute to the circulation of measles virus. This study demonstrated the usefulness of RT-PCR on non-invasive clinical samples for the investigation of measles cases.

Detection of low-avidity immunoglobulin G in oral fluid samples: new approach for rubella diagnosis and surveillance.

Low-avidity rubella immunoglobulin G (IgG) was detected in oral fluid samples from 30 of 32 rubella IgM-positive patients (sensitivity, 94%) and from 4 of 34 IgM-negative patients (specificity, 88%). Measuring IgG avidity in oral fluid samples could improve the reliability of rubella surveillance when the incidence of the disease and the positive predictive value of IgM tests are low.

Seroprevalence of parvovirus B19 in urban Chilean children and young adults, 1990 and 1996.

An immunofluorescence test for detecting parvovirus B19 IgG was developed by infecting insect cells with recombinant baculovirus expressing the capsid protein VPI. The test was used to study the prevalence of antibodies in 725 healthy children and young adults living in Santiago, Chile. In total, 248 sera were taken in 1990 and 477 in 1996. The seroprevalence was low in children less than 5 years old (3% in 1990 and 21% in 1996). It rose during school age to a prevalence around 50%, reaching 60% in young adults. No differences were found between genders. There was a statistically significant higher seroprevalence in the low socioeconomic status group in 1990 samples, but this was not observed in 1996. The higher prevalence observed in children less than 5 years of age in 1996 compared with 1990 could be explained by the occurrence of intervening epidemics of parvovirus B19 infection.

Cyclophosphamide/fludarabine (CF) is active in the treatment of mantle cell lymphoma.

The purpose of this study was to determine the efficacy and toxicity of the cyclophosphamide and fludarabine (CF) regimen in patients with newly diagnosed and relapsed/refractory mantle cell lymphoma (MCL). Thirty patients with pathologically confirmed MCL were treated with the CF regimen. Ten (33%) had no prior therapy, six (20%) had one previous regimen, and 14 (47%) received two or more prior regimens. Ninety cycles of CF with a median of 3 cycles/patient (range, 1-5 cycles) were administered to patients with MCL. Nine patients (30%) had a complete response (CR) and 10 (33%) had a partial response (PR) for an overall response rate (RR) of 63%. The median failure-free survival (FFS) and overall survival (OS) was 4.8 months and 17.5 months, respectively. When patients were analyzed based upon the number of previous treatments (0, 1, or 2 or more), those with no previous treatment (n=10) had an overall response of 100%, with 70% CR. The median FFS was 28.1 months and the median OS for this group has not been reached at 42.3+ months. Hematologic and infectious toxicity were the major toxicities encountered with the CF regimen. Grade 3-4 neutropenia, thrombocytopenia and anemia were seen in 50%, 37%, and 36% of patients, respectively. There were 13 episodes of grade 3 infections. There was no treatment related mortality, In conclusion, the high response rate associated with the CF regimen merits further investigation in previously untreated patients with MCL, particularly in those who are not candidates for aggressive therapy.

Measles virus strains circulating in Ethiopia in 1998-1999: molecular characterisation using oral fluid samples and identification of a new genotype.

A measles outbreak in December 1998 in Bedelle (vaccine coverage <40%) and two sporadic cases in Addis Ababa, Ethiopia, were investigated. Paired serum and oral fluid samples were collected 2-8 days after the onset of symptoms. A total of 53 of 55 outbreak cases and both sporadic cases were positive for serum measles virus-specific IgM. Oral fluid measles-specific IgM was positive in 71% of cases collected up to 5 days after onset and in 90% collected at 6-8 days. By contrast, 100% of oral fluid samples were positive for measles virus RNA by RT-PCR, suggesting that early collection of samples favoured the detection of measles virus RNA by RT-PCR. The measles virus strain in the outbreak was identified as genotype D4. One strain from a sporadic case was also genotype D4; the strain from the other sporadic case was assigned to clade D but was distinct. The degree of divergence from recognised clade D strains suggested that, together with three strains from the United Kingdom, it represents an additional genotype of clade D (GenBank accession numbers AF280800-280807).

Efficient isolation of mumps virus from a community outbreak using the marmoset lymphoblastoid cell line B95a.

The incidence of mumps infection in the UK was reduced greatly by vaccination as a component of MMR vaccine, but cases and outbreaks continue to occur. Although in specialised laboratories RT-PCR is available for detection of mumps virus RNA in clinical samples, in routine laboratories virus isolation remains a standard method for diagnosing mumps virus infection. Furthermore, isolation of mumps virus strains circulating currently is important for monitoring the ability of vaccine-induced antibody to neutralise any genotypes recognised recently and to detect any changes in phenotype. In this study we compared rhesus monkey kidney (RMK) cells with the cell line B95a for mumps virus isolation from twenty throat swabs collected during a mumps outbreak in a religious community with low MMR coverage. Mumps virus was isolated from eight cases (40%), six were positive in both cell cultures and two in only one, all positive samples being collected within 2 days of onset. Virus growth in B95a cells was detected by the production of a syncytial cytopathic effect, and confirmed by an indirect fluorescent antibody test using a mumps monoclonal antibody. The B95a cell line was found to be equally as sensitive for mumps isolation as RMK cells, which are regarded as the 'gold standard', thus providing an alternative to the use of primary animal cell culture.

Has oral fluid the potential to replace serum for the evaluation of population immunity levels? A study of measles, rubella and hepatitis B in rural Ethiopia.

OBJECTIVE: To assess the suitability of using oral-fluid samples for determining the prevalence of immunity to vaccine-preventable infections. METHODS: Paired blood and oral-fluid samples were obtained from 853 individuals of all ages from a rural Ethiopian community. Oral fluid around the gums was screened for measles- and rubella-specific antibodies using enhanced IgG antibody capture (GAC) enzyme-linked immunosorbent assays (ELISAs), and for anti-HBc antibodies using a prototype GACELISA. IgG antibodies in serum to measles, rubella and HBc were determined using commercial ELISAs. FINDINGS: Relative to serum, oral fluid assay sensitivity and specificity were as follows: 98% and 87% for measles, 79% and 90% for rubella, and 43% and 87% for anti-HBc. These assay characteristics yielded population prevalence estimates from oral fluid with a precision equal to that of serum for measles (all ages) and rubella (ages < 20 years). CONCLUSION: Our results suggest that oral fluid could have the potential to replace serum in IgG antibody prevalence surveys. Further progress requires assessment of variation in assay performance between populations as well as the availability of standardized, easy to use assays.

Human parvovirus B19 infection in HIV-positive patients.

Parvovirus B19 infects predominantly erythroid cells, leading to transient inhibition of erythropoiesis. Immunocompromised patients may be unable to produce neutralizing antibodies and may develop severe chronic anemia. Epidemiological studies done on Niterói population showed that B19 infection occurs periodically in late spring and summer. We report a study from 55 HIV infected patients attending an infectious diseases outpatient clinic in this city during a 5-month period in which B19 circulation was well documented. All patients were under anti-retroviral therapy. No anti-B19 IgM was found, but a high prevalence of IgG anti-B19 (91%) was observed. In six patients, B19 DNA was found by dot-blot hybridization techniques, but this was not confirmed by PCR. None of these 6 patients manifested anemia and only one had CD4 cell count below 200 x 10(7)/L. We conclude that persistent infection causing anemia is an infrequent finding in our HIV positive patients under drug therapy.

A comparison of oral fluid collection devices for use in the surveillance of virus diseases in children.

Three oral fluid collection devices (OraSure, Omni-SAL and Oracol) were compared in terms of the quality of oral fluid collected by each device for antibody testing and their acceptability to participants. Participants (143 children aged 3.5-5 y from North Hertfordshire, UK, who had recently received DTaP and MMR vaccination) were randomised to use one of the three types of collection device. Oral fluid was collected by a parent who completed a short questionaire recording information on ease of use and willingness to use the device again. A matching serum sample was collected by a nurse. Oral fluid samples were screened for total IgG and IgM by ELISA and for rubella specific IgG and parvovirus specific IgG by radioimmunoassay. Serum samples were screened for rubella specific IgG and parvovirus B19 specific IgG by ELISA. 87.4% (125) of participants provided a matching oral fluid and serum sample. Of these, 100% (125) and 10.4% (13) had serum IgG specific for rubella and parvovirus B19, respectively. The Oracol device provided oral fluid samples with the highest geometric mean titres of total IgG and IgM and with rubella specific IgG results which correlated most closely with those of matching sera. A higher proportion of parents found the Oracol and OraSure devices easier to use than the Omni-SAL (P<0.001) and the proportion who would not take another test was higher for the Omni-SAL than for the Oracol or Orasure. Oral fluid samples collected by each of the devices gave qualitative results acceptable for surveillance and epidemiological studies of rubella and parvovirus B19. The highest quality oral fluid sample for antibody testing in terms of total IgG and IgM concentration and rubella specific IgG concentration was collected by the Oracol. The acceptability to participants of both the Oracol and OraSure was high. As the cheapest device available, the Oracol is the preferred oral fluid collection device for studies involving children in the UK.

Human parvovirus B19 infection in HIV-positive patients

Parvovirus B19 infects predominantly erythroid cells, leading to transient inhibition of erythropoiesis. Immunocompromised patients may be unable to produce neutralizing antibodies and may develop severe chronic anemia. Epidemiological studies done on Niterói population showed that B19 infection occurs periodically in late spring and summer. We report a study from 55 HIV infected patients attending an infectious diseases outpatient clinic in this city during a 5-month period in which B19 circulation was well documented. All patients were under anti-retroviral therapy. No anti-B19 IgM was found, but a high prevalence of IgG anti-B19 (91%) was observed. In six patients, B19 DNA was found by dot-blot hybridization techniques, but this was not confirmed by PCR. None of these 6 patients manifested anemia and only one had CD4 cell count below 200 x 10(7)/L. We conclude that persistent infection causing anemia is an infrequent finding in our HIV positive patients under drug therapy.

O parvovírus B19 infecta predominantemente células eritróides, causando inibição transitória da eritropoiese. Pacientes imunocomprometidos podem ser incapazes de produzir anticorpos neutralizantes, evoluindo com grave anemia crônica. Estudos epidemiológicos da população de Niterói mostraram que a infecção ocorre periodicamente no final da primavera e no verão. Descrevem-se 55 pacientes infectados pelo HIV atendidos num ambulatório de doenças infecciosas nesta cidade num período de cinco meses, no qual a circulação do parvovírus B19 foi documentada. Todos os pacientes estavam sob terapia anti-retroviral. Não se encontrou IgM anti-B19, mas notou-se uma prevalência alta de IgG anti-B19 (91%). Em seis pacientes verificou-se a presença de DNA do B19 por hibridização em dot-blot, o que não se confirmou por PCR. Nenhum destes seis pacientes tinha anemia, e apenas um tinha células CD4 abaixo de 200 x 107/L. Conclui-se que infecção persistente causando anemia é um achado infreqüente em nossos pacientes HIV positivos sob terapia medicamentosa.

Diagnosis of rubella infection by detecting specific immunoglobulin M antibodies in saliva samples: a clinic-based study in Niterói, RJ, Brazil.

This study was designed to investigate whether saliva could be a feasible alternative to serum for the diagnosis of recent rubella infection in a clinic setting. Forty-five paired blood and saliva samples collected 1 to 29 days after onset of illness were tested for specific immunoglobulin (Ig) M by antibody-capture radioimmunoassay (MACRIA). Rubella IgM was detected in all serum samples and in 38 (84.4%) saliva specimens. Forty-six serum and saliva samples from other patients with rash diseases were tested by MACRIA for control purposes and two saliva specimens were reactive. The saliva test had specificity of 96%. These results indicate that salivary IgM detection may be a convenient non-invasive alternative to serum for investigation of recent rubella cases, especially for disease surveillance and control programmes.