Motivations and concerns of patients with access to genetic testing for hereditary pancreatitis.

OBJECTIVES: Direct DNA testing is now available for hereditary pancreatitis (HP). This study aimed to identify the factors that motivated individuals to participate in research and to determine how research participants used their genetic test results. METHODS: A survey was mailed to 247 participants (110 male, 137 female) who were > or =18 yr of age and living in the US. Data analysis was primarily a description of frequency distribution of the responses. RESULTS: Ninety-one of 247 participants (37%) completed the survey. Of the 55 female and 36 male respondents, 60% were 31-55 yr old, and a total of 54% tested positive for HP. The most common reason for participating in research was "to help a relative/family member" (61%), and genetic testing was pursued because of "the disturbance of seeing affected relatives" (48%) and "the desire to help future generations" (33%). Perceived risk of developing HP in the future was the least important motivating factor in seeking genetic testing. Sixty-two percent of respondents had received their genetic test results. All but one chose to share their results with at least one person: most often with family members (96%) and physicians (62%), and least often with insurance companies (4%). The most common influential factor in withholding information was "the fear of insurance discrimination" (23%). CONCLUSIONS: The major motivations to participate in the HP genetic research study were to obtain genetic testing and to help current family members and future generations. The major concern was insurance discrimination. Participants clearly appreciate the availability of genetic testing for HP. These results suggest that a mechanism to disclose results to research participants should be considered, and effective ways to protect at-risk individuals from insurance discrimination must remain a genetics health care priority.

Faulty washers and soiled micropipettors may generate false positive serological results.

BACKGROUND: Serological markers such as HBsAg and anti-HIV may be present in serum at very high concentrations and this may give rise to erroneous diagnoses due to cross-contamination. OBJECTIVES: To investigate poor equipment maintenance and use, including contamination with human serum, as a potential source of erroneous assay results. STUDY DESIGN: The potential of microtitre plate washers and micropipettors to transfer material between microplate wells and between specimens was examined. For the study of micropipettors we recruited 19 UK diagnostic laboratories. RESULTS: Four out of seven plate washers in use, until adjusted, had the potential to cause false positive HBsAg reactions. The centering of the probes that delivered the wash fluid, delivery pressure, wash volume and the use of a pre-programmed card to direct the washing procedure were important variables. We investigated soiling of tip cones of micropipettors. In every laboratory human IgG could be detected in at least a third of eluates from micropipettor tip cones; only 31 (14%) of 222 showed no evidence of contamination with human serum. Only one laboratory submitted eluates devoid of specific antibodies. Anti-HAV was the marker most commonly found (n = 68), followed by HBsAg (n = 27) and anti-HIV (n = 20). Seven micropipettor eluates from two laboratories were radioactively contaminated. CONCLUSIONS: Recommended precautions are regular checking, cleaning and servicing of equipment, care in interpreting weak reactions, reference back to serum left on the clot of the original specimen and testing of a follow up specimen. Poorly maintained immunoassay equipment can readily generate false positive results due to low-level cross-contamination, particularly with the current highly sensitive HBsAg and anti-HIV assays.

How valuable are IgA and IgM anti-HIV tests for the diagnosis of mother-child transmission of HIV in an African setting?

BACKGROUND: Babies born to HIV-infected mothers retain anti-HIV of maternal origin until 15-18 months of age. Because of this, HIV proviral DNA and p24 antigen measurements have become the methods of choice for timely diagnosis of HIV infection in infancy. They are, however, too expensive for widespread use in the developing world. OBJECTIVE: To evaluate a simple, inexpensive serological method for diagnosing mother-child transmission of HIV, in an African population, which takes account of the effects of placental transfer of maternal antibody and continued exposure to HIV through breast-feeding. STUDY DESIGN: Plasma specimens for a prospective study of mother-to-infant transmission of HIV in rural Zaire were collected at birth, 3, 6, 9, 12, 18 and 24 months from 21 infected infants (PP group), 21 uninfected infants (PN group) born to seropositive mothers and 21 control infants (NN group) born to uninfected mothers. The specimens were retrospectively tested for IgG, IgM and IgA anti-HIV by immunoglobulin class-specific capture EIAs, and by a commercial anti-HIV EIA. RESULTS: In neonatal specimens, IgA and IgM anti-HIV were present, respectively, in 13 of 14 (97%) and 8 of 14 (57%) of the PP group and in 6 of 11 (55%) and 2 of 11 (18%) of the PN group. Later, at 3 months and older, IgA and IgM anti-HIV were only detected in the PP group. They peaked at 18 months (93%) and 24 months (67%) respectively. Of the 21 PP group children, 8 (38%) were transiently IgG anti-HIV-negative in the first year, indicating that infection had probably taken place after birth; four of the 8 had no detectable IgA anti-HIV during the first year. None of the specimens collected from the NN group babies were reactive for IgA, IgM or IgG anti-HIV. CONCLUSIONS: IgA and IgM anti-HIV may be passively transferred across the placenta. Where breast-feeding is prevalent, about half of the transmissions may occur after birth, thus delaying the diagnosis of mother-child transmission. Nevertheless, this simple, cheap IgA anti-HIV, EIA identified 65% of transmissions by 9 months of age, and 93% at 18 months of age. It is a more useful marker than IgM anti-HIV, and gave a much more rapid answer than did tests for IgG anti-HIV seroreversion.

GACPAT HIV 1 + 2: a simple, inexpensive assay to screen for, and discriminate between, anti-HIV 1 and anti-HIV 2.

A simple and cheap assay suitable for screening for anti-HIV 1 and anti-HIV 2 and discriminating between them was evaluated. In it specimens are incubated in U-bottomed microplate wells coated with anti-human IgG for 30 min at room temperature. After washing, 100 microliters of a 1 in 50 dilution of HIV 1-coated gelatin particles (Serodia-HIV 1/2, Fujirebio) are added. Settling patterns are read on the second day: A positive reaction is indicated by adherence of the particles and a negative by a button. The HIV 1 particles are then washed away and HIV 2 particles added. Anti-HIV 2 reaction patterns are read on the third day. To assess the performance of the modified "GACPAT HIV 1 + 2" assay a panel of 1,621 serum/plasma specimens was used. It comprised validated anti-HIV 1 positive (n = 220), anti-HIV 2 positive (n = 214), dual anti-HIV 1/anti-HIV 2 positive (n = 11), and anti-HIV negative (n = 1,176) serum/plasma specimens. All 434 specimens that contained anti-HIV 1 or anti-HIV 2 reacted positively with the homologous particles. The 11 dually positive specimens reacted positively with both HIV 1 and HIV 2 particles. Five (2.3%) anti-HIV 1 and five (2.3%) anti-HIV 2 positive specimens gave positive reactions with both particle types, but none of the five cross-reactive anti-HIV 2 specimens were dually reactive when the order of particle addition was reversed.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of anti-HIV in saliva and urine at the time of seroconversion.

To determine whether there is a delay between the appearance of anti-HIV in serum/plasma and its detection in saliva and urine, salivary and urine specimens were collected from nine individuals who, on the basis of increasing IgG anti-HIV reactivity, Western blot band patterns and presence of strong IgM anti-HIV reactivity in their serum specimens, were believed to have recently become anti-HIV-positive. Serum from 8 of these patients and 3 commercial panels of plasma specimens collected during seroconversion were diluted to mimic the low immunoglobulin concentrations present in saliva and urine and tested in Wellcozyme HIV 1 + 2 GACELISA and four commercial EIAs intended for testing serum specimens. The 9 pairs of saliva and urine specimens were collected between 4 and 43 days (median 24 days) after the first evidence of seroconversion. All were reactive by Wellcozyme HIV 1 + 2 GACELISA and gave optical density/cut off (OD/CO) ratios in the range 3.8 to 9.8 (median 5.2) for dribbled saliva and 2.4 to 10.1 (median 6.3) for urine. Salivary specimens taken with commercial collection devices gave OD/CO ratios in the range 1.6 to 10.6 (median 5.9). In the serum/plasma specimens Wellcozyme HIV 1 + 2 GACELISA detected anti-HIV at higher dilutions than the other assays, often with a 100-fold or more difference. Saliva and urine specimens were all strongly reactive by Wellcozyme HIV 1 + 2 GACELISA. We therefore predict that it would first detect anti-HIV in salivary and urine specimens at about the same time as it becomes detectable in serum/plasma but that other commercial EIAs would not.

HIV infection in injecting drug users attending centres in England and Wales, 1990-1991.

OBJECTIVE: To monitor trends in HIV infection and associated risk behaviours in injecting drug users (IDU) in England and Wales. DESIGN: Ongoing voluntary unlinked anonymous cross-sectional survey. METHOD: IDU attending centres in 1990 and 1991 were invited to complete a brief questionnaire requesting demographic and behavioural information, and to provide a saliva sample to be tested for antibodies to HIV and to the core antigen of hepatitis B virus (HBV). RESULTS: In 1990, 1.2% (19 out of 1543) of samples from 33 centres, and in 1991 1.8% (25 out of 1417) of samples from 37 centres contained antibody to HIV. Antibody t9 HBV core-antigen was found in 33 and 31% of IDU in 1990 and 1991, respectively. The prevalence of HIV infection in IDU attending centres in London (4.2%) was higher than in those attending centres elsewhere (0.8%). The prevalence of HIV infection in 1991 varied between individual centres from 0 to 10.6%, and at many centres outside London no IDU were infected with HIV. In the same year the prevalence of past infection with HBV varied from 14 to 54%, and IDU who had evidence of HBV infection were found among attenders in nearly all centres. The prevalences of sharing injecting equipment and risky sexual behaviour were high at many centres. The prevalence of HIV infection was higher in IDU who had started to inject in 1985 or earlier, than in those who started injecting later. In each year, approximately half the IDU surveyed reported having had a voluntary confidential HIV-antibody test, and the prevalence of HIV infection was five times higher in those tested than in those who had not been tested. CONCLUSIONS: HIV prevalence in IDU attending centres in England and Wales was low in 1990-1991. There is some indication that IDU have modified their injecting or sexual behaviour, but even at existing reduced levels of risk behaviour, transmission can occur in HIV is introduced into previously unexposed groups.

Novel assay for the detection of immunoglobulin G antihuman immunodeficiency virus in untreated saliva and urine.

Epidemiological evidence and laboratory studies indicate that human immunodeficiency virus type 1 (HIV 1) is rarely, if ever, transmitted in saliva or urine. In that both specimens are easy to collect, each may be a useful alternative to serum specimens for anti-HIV screening. A rapid, simple, and robust IgG-capture enzyme-linked immunosorbent assay (GACELISA) suitable for the detection of anti-HIV 1 and 2 in saliva and urine was developed. Following optimisation of the assay, 177 salivary and 568 urine specimens collected from individuals of known serostatus were investigated. The assay was 100% sensitive on 50 salivary (median OD/CO = 8.9) and 126 urinary (median OD/CO = 8.6) specimens collected from anti-HIV-positive patients. The specificity was 100% on 127 salivary specimens (median OD/CO = 0.37) and 422 urinary specimens (median OD/CO = 0.39) collected from anti-HIV-negative individuals. These findings demonstrate that GACELISA HIV 1 + 2 tests on saliva or on urine are an accurate alternative to a conventional anti-HIV test of blood. This assay is satisfactory for surveillance purposes and, with appropriate precautions, could be used clinically.

Human immunodeficiency virus: GACPAT and GACELISA as diagnostic tests for antibodies in urine.

Testing for antibodies to human immunodeficiency virus (HIV) in urine may be of use in epidemiological studies. We collected 336 paired urine and serum samples from subjects in Karonga District, northern Malawi: 86 (25.6%) of the serum samples were HIV positive. Serum results were compared with those from immunoglobulin (Ig) G antibody-capture particle adherence tests (GACPAT) and IgG antibody-capture enzyme-linked immunosorbent assay (GACELISA) on the corresponding urine samples performed independently in 2 laboratories. The minimum observed relative sensitivity and specificity of GACPAT were 96.5% and 98.8% respectively; the specificity could be raised by using a protocol involving re-testing of reactive samples to determine end-point titre. For GACELISA, the observed relative sensitivity and specificity were 98.8% and 99.2% respectively. Such assays may be useful either as a primary screen in populations where urine samples are considerably easier to obtain than serum samples, or as an alternative test for individuals unwilling to provide a serum sample.

A new system for cotside display and analysis of the preterm neonatal electroencephalogram.

Continuous EEG monitoring is considered to be a sensitive indicator of changes in cerebral function. This paper describes a system for cotside display and analysis of EEG discontinuity and amplitude in one-minute epochs, with provision for simultaneous recording of the EEG. It has been successfully used to monitor continuously the EEGs of more than 30 babies in a neonatal intensive care unit for periods of up to nine days. This system rapidly provides indications of changes in cerebral function, which can allow early intervention and possible prevention of morbidity.

Preliminary report: accurate assays for anti-HIV in urine.

Untreated urine specimens from 358 patients (344 attending genito-urinary medicine clinics, 14 haemophiliacs) and 353 blood donors were tested blind by a simple IgG-capture particle-adherence test (GACPAT) and a rapid IgG-capture enzyme-linked immunosorbent assay (GACELISA) for antibody to human immunodeficiency virus (anti-HIV). All 158 urine specimens from seropositive subjects were anti-HIV positive by GACPAT and 157 of them (99.4%) were positive by GACELISA. Tests on 553 urine specimens from seronegative subjects gave two repeatable false-positive reactions by GACPAT (0.4%) and none by GACELISA. By means of a modified procedure anti-gp160 was detected by commercial western blot in the urine of 44 of 45 seropositive subjects examined. IgG-capture assays will detect anti-HIV in unconcentrated urine and so allow a diagnosis in circumstances when blood sampling is impracticable.

Localized cerebral infarction in the premature infant: an ultrasound diagnosis correlated with computed tomography and magnetic resonance imaging.

Findings on cranial ultrasonography strongly suggested the diagnosis of a localized infarct in four premature infants. CT was performed to differentiate between hemorrhagic and nonhemorrhagic lesions, and magnetic resonance imaging was used to obtain information about the late effect of the lesions. The clinical findings, imaging findings, and later outcome in these premature infants were compared with the existing knowledge of this type of lesion in the full-term infant. A localized infarct appears to carry a good prognosis in the premature infant and should be differentiated from other types of lesions, such as periventricular leukomalacia or parenchymal hemorrhage, which are more common in the premature infant and carry a worse prognosis.

Three-year follow-up (1983-1986) of children undergoing bilateral grommet insertion in Sheffield.

A retrospective study with review, after 3 years, of 43 children between the ages of 4 and 13 years, who had bilateral otitis media with effusion treated surgically purely by the insertion of grommets is described. The results shows that the younger the child at initial grommet insertion, the greater the likelihood of more than 1 grommet insertion being required (P less than 0.05). A younger patient is likely to make a greater number of outpatient visits (P less than 0.05), and the number of outpatient visits correlates with the number of grommets inserted (P less than 0.01). At 3 years, 49% of children remained on regular outpatient follow-up, while 34% of children had persisting effusion in 1 or more ears. Whilst grommets are in place, otorrhoea is not adversely influenced by swimming. The role of adenoidectomy in the management of otitis media with effusion is not assessed by this study.

Continuous 4-channel EEG monitoring: a guide to interpretation, with normal values, in preterm infants.

A system is described for the rapid analysis of the extensive EEG data produced by continuous 4-channel monitoring. Using this system, the initial EEGs of 44 low-risk preterm infants between 26 and 37 weeks gestation have been analysed and quantified in order to establish standard values. This provides a basis for assessment of the acute EEG as an index of cerebral function in high-risk or abnormal preterm infants.

Neurological, electrophysiological and MRI abnormalities in infants with extensive cystic leukomalacia.

Twenty infants, diagnosed by cranial ultrasound as having extensive cystic leukomalacia, had visual evoked responses (VER) and electroencephalograms (EEG) in the neonatal period and MRI scans later in infancy. The early ultrasound findings and results from the electrophysiological tests were correlated with later MRI findings and functional abilities. In infants with periventricular leukomalacia (PVL), the cysts were usually no longer visible by ultrasonography, beyond 40 weeks postmenstrual age (PMA), but later MRI scans showed a consistent pattern of delayed myelination around the irregularly dilated occipital horns of the lateral ventricles. VER's were present in the neonatal period and vision was maintained, although all infants developed a marked squint. EEG's were either normal or abnormal initially, but improvement was noted within several weeks. In those with subcortical or mixed lesions, cysts were noted to persist beyond 40 weeks PMA. Later MRI scans showed very poor myelination, with poor progress on subsequent scans and cortical atrophy. VER's were absent and all infants later became cortically blind. EEG's were severely abnormal and recovery was very poor. The infants with PVL developed spastic diplegia with moderate developmental delay, while those with mixed or subcortical lesions developed quadriplegia with severe mental retardation. An integrated approach, consisting of ultrasound imaging and electrophysiological recordings in the neonatal period and MRI imaging later in infancy, may provide a more reliable prediction of the pattern of later deficits.

Electrical response audiometry: a survey of its effect on the diagnosis and management of deafness in children.

The effect of the use of electric response audiometry (ERA) on the diagnosis and management of children has been investigated. A retrospective method was employed using the notes of the first 102 hearing assessments in 1978 where an ERA test was performed. The results show that the effect on diagnosis has been to improve the degree of certainty rather than to re-classify patients as deaf or normal. The effect on management has been to reduce by 24% the number of patients that require repeat assessment. These effects are more pronounced in the '0--1 age group' as opposed to the 'above 1 year' age group.

Immunization of sheep with larval antigens of Lucilia cuprina.

Sheep were immunized with antigens extracted from third-instar larvae of L. cuprina. This procedure produced substantial titres of circulating antibody as measured by solid-phase radioimmunoassay or immunodiffusion or by both techniques. However, immunization did not confer protection against subsequent implant challenge with first-instar larvae. In vitro studies indicated that pooled sera from immunized sheep (mean immunodiffusion titre = 3) significantly reduced larval survival. Antigen specificity and the modulating effects of concomitant humoral responses to larval challenge are discussed in relation to the findings.

Immunoglobulin G antibodies to the antigens of Lucilia cuprina in the sera of fly-struck sheep.

A solid-phase radioimmunoassay was used to demonstrate that sheep with myiasis caused by the larvae of the Australian sheep blowfly, L. cuprina, had serum IgG antibodies to antigens present in an extract of the ground-up larvae. Previously struck animals demonstrated a more severe myiasis than their unstruck counterparts when both groups were subjected to a standard larval challenge. The effects of immunosuppressive therapy were expressed in terms of a decrease in the total number of larvae growing to maturity and in the area of fly strike produced.