Molecular genetic analyses of parapoxviruses pathogenic for humans

The current members of the genus parapoxvirus are orf virus (ORFV), bovine papular stomatitis virus (BPSV), pseudocowpoxvirus (PCPV) and parapoxvirus of red deer in New Zealand (PVNZ). BPSV and PCPV are maintained in cattle while ORFV is maintained in sheep and goats, but all three are zoonoses. Only the recently reported PVNZ has yet to be recorded as infecting humans. Tentative members of the genus are camel contagious ecthyma virus, chamois contagious ecthyma virus and sealpoxvirus. The separation of the parapoxviruses into 4 distinct groups has been based on natural host range, pathology and, more recently, on restriction endonuclease and DNA/DNA hybridisation analyses. The latter studies have shown that the parapoxviruses share extensive homology between central regions of their genomes, but much lower levels of relatedness within the genome termini. The high G + C content of parapoxvirus DNA is in contrast to most other poxviruses and suggests that a significant genetic divergence from other genera of this family has occurred. DNA sequencing of portions of the genome of ORFV, the type species of the genus, has allowed a detailed comparison with the fully sequenced genome of the orthopoxvirus, vaccinia virus (VACV). These studies have provided a genetic map of ORFV and revealed a central core of 88 kbp within which the genomic content was strikingly similar to that of VACV. This conservation is not maintained in the genome termini where insertions, deletions and translocations have occurred. The characterisation of specific ORFV genes may lead to the construction of attenuated vaccine strains in which genes such as those with the potential to interfere with the immune response of the host have been deleted. The current ORFV vaccines are living unattenuated virus and vaccination lesions produce virus which contaminates the environment in a manner similar to natural infection. The virus in scab material is relatively resistant to inactivation and this virus both perpetuates the disease in sheep and provides the most likely source of human infections. A vaccine which immunises animals without perpetuating the disease could be the best way of reducing the incidence of ORFV infection of humans. It is likely that protection against infection by ORFV is cell mediated and will require the endogenous production of relevant antigens. We have recently constructed a series of VACV recombinants each of which contains a large multigene fragment of ORFV DNA. Together the recombinants represent essentially all of the ORFV genome in an overlapping manner. Vaccination of sheep with the recombinant library provided protection against challenge with virulent ORFV. Further studies with this library may enable dominant protective antigens of ORFV to be identified and lead to their incorporation into a subunit vaccine.

Dissociative symptoms in panic disorder

The present study examined the prevalence and correlates of dissociative symptoms in patients with panic disorder and patients with other nonpanic anxiety disorders. A total of 56 patients with anxiety disorders (13 with panic disorder alone, 16 with comorbid panic and other anxiety, and 27 with other anxiety disorders) were assessed with structured clinical interviews and a battery of questionnaires. Although 69% of patients with panic disorder experienced depersonalization or derealization during their panic attacks, panic disorder patients were no more likely to experience dissociative experiences as assessed by the Dissociative Experience Scale than patients with other anxiety disorders. In the entire sample, the prevalence of dissociative experiences was very low and well within nonpathological ranges. The correlates of dissociative symptoms were severity of depression, social anxiety, and personality disorders. The implications of these findings for conceptualizing the nature of dissociative symptoms within an anxiety population are discussed.

Cognition and multiple sclerosis: a historical analysis of medical perceptions

The earliest descriptions of multiple sclerosis (MS) rarely distinguished cognitive impairment from the general category of "mental symptoms", which also encompassed a broad range of affective disorders. Case-study methods led to disputes about the extent and nature of these symptoms, exacerbated by different national medical traditions. Appropriate scientific methods were only used to investigate cognitive performance in a modest number of studies up to the 1960s, and it was being argued as late as the mid 1970s that affective processes rather than cognitive processes were the key to understanding the psychological aspects of MS. However, the early 1980s, saw major developments in test procedures for the detection of subtle and selective cognitive changes, in the use of brain imaging techniques, and in collaboration between neurologists and neuropsychologists. Pressure to use research findings to improve patients' daily lives suggests a need to reconsider the connection between affective and cognitive processes in MS.

Effects of an immunostimulating agent on acute exacerbations and hospitalizations in patients with chronic obstructive pulmonary disease. The PARI-IS Study Steering Committee and Research Group. Prevention of Acute Respiratory Infection by an Immunostimulant

The PARI-IS Study is a double-blind placebo-controlled randomized clinical trial to study the effect of an immunostimulating agent to prevent acute respiratory exacerbation in patients with COPD. Three hundred eighty-one ambulatory patients (190 placebo and 191 immunostimulant) were followed at home for 6 mo by experienced research nurses. The risk of having at least one episode of acute exacerbation (primary outcome) was similar in the two groups (p = 0.872). In contrast, the total number of days of hospitalization for a respiratory problem was 55% less in the group treated with OM-85 BV (287 d) than in the group treated with placebo (642 d). Patients treated with OM-85 BV spent an average of 1.5 d in hospital compared with 3.4 d for patients treated with placebo (p = 0.037). The risk of being hospitalized for a respiratory problem was 30% lower in the treated group (16.2%) than in the placebo group (23.2%); p = 0.089. Eight deaths were observed: two in patients treated with OM-85 BV and six in patients treated with placebo (p = 0.153). During the course of the study dyspnea improved slightly in patients treated with OM-85 BV, whereas it deteriorated slightly in patients receiving placebo (p = 0.028). These results suggest that this immunostimulating agent may be beneficial for patients with COPD by reducing the likelihood of severe respiratory events leading to hospitalization.

Valuing health status using VAS and TTO: what lies behind the numbers?

It is well known that different methods of eliciting the valuations attached to various health states, such as the Visual Analogue Scale (VAS) and the Time Trade Off (TTO), yield different results. This study gathers qualitative data from a group of 43 respondents who had previously taken part in a large scale national study which set out to elicit the values attached by individuals to various health states using both the VAS and the TTO techniques. The findings of this study raised three questions which are of particular interest here: (1) Why are some states that are rated better than dead on the VAS often rated as worse than dead in TTO? (2) Why are some respondents unwilling to trade off any time at all in order to avoid a health state that they place below full health on the VAS? (3) Why are TTO valuations of older respondents for the more severe health states lower than those of the younger age groups? This study has uncovered qualitative evidence on each of these three key issues. Regarding the first question, many respondents did not appear to interpret a better than dead VAS score as a strict preference for spending 10 years in a health state over immediate death. Several different factors appeared to contribute towards this, an important one being the tendency of respondents to ignore the duration of the health state during the VAS task. Regarding the second question, there is evidence of the existence of a "threshold of tolerability" below which states would have to fall before some respondents would be willing to give up any time at all on the TTO. Regarding the last question, it appears that older respondents are less likely to find the worse than dead TTO scenario plausible than those in the younger age groups. However, whilst this may explain why older respondents attach lower worse than dead valuations to health states, it does not appear to account for the entire difference in TTO valuations between the two age groups. In addition, it appears that older respondents may be less prepared to live for the next 10 years in a diminished health state.

Analysis of the human Ig isotype response to individual transferrin binding proteins A and B from Neisseria meningitidis

Subcapsular antigens, including transferrin binding proteins, are being considered as potential vaccines against serogroup B meningococci. This study examined the human isotype antibody responses in cases of meningococcal disease to meningococcal TbpA (transferrin binding protein A) and TbpB (transferrin binding protein B) from two strains (SD and B16B6) expressing high and low molecular mass TbpB respectively. TbpA isolated from both strains were recognised more frequently and higher durable ELISA absorbance values were detected than those detected against TbpB from either strain. These antibody responses to Tbps were independent of the infecting meningococcal strain type. The antibody response to the four proteins was highly variable between individuals and differed significantly against all four antigens. The variability of immune responses to each Tbp from the two strains suggests that a successful vaccine would need to include TbpA and TbpB from a number of strains.

Sleep-disordered breathing and hypertension: past lessons, future directions

That obstructive sleep apnea syndrome is an independent risk factor for the development of hypertension was established in the 1970s, and recent works on large samples have confirmed this fact. Investigations of the mechanisms that may lead to the development of hypertension with sleep-disordered breathing will allow not only confirmation of the relationship but also creation of better treatment. There is a multigenic basis of blood pressure regulation, and genetic factors play a role in the development of sleep-disordered breathing. Genes that may have little role in the physiologic variation of blood pressure may be more important in the manifestation of pathology. And one hypothesis is that genes involved in the development of a morphotype may also have a role in the development of hypertension. Furthermore, sleep-disordered breathing may be associated with abnormal sympathetic discharge during sleep, as shown by microneurography. This mechanism may explain how a sleep disorder leads to hypertension, but impairment of vascular endothelial controls may also be involved. Investigation of vascular endothelial vasodilation as demonstrated by forearm plethysmography or the dorsal hand vein technique indicates that impairment of endothelium-dependent vasodilation during wake is associated with sleep-disordered breathing. This endothelium-dependent vasodilation appears to be more frequently impaired than the endothelium-independent vasodilation, and the former impairment can be reversed by nasal continuous positive airway pressure. These findings are supportive fo the role of sleep-disordered breathing in the development of hypertension in man.

Comparison of two methods of screening for genital chlamydial infection in women attending in general practice: cross sectional survey

OBJECTIVES

To estimate the prevalence of Chlamydia trachomatis in asymptomatic women attending general practice: to assess the potential of the ligase chain reaction as a screening tool; and to evaluate selective screening criteria.

DESIGN

Cross sectional survey.

SETTING

Four general practices in northeast London.

SUBJECTS

890 women aged 18-35 years attending general practice for a cervical smear or a "young well woman" check between October 1994 and January 1996. The women were tested for C trachomatis with confirmed enzyme immunoassay (endocervical specimens) and ligase chain reaction assay on urine specimens.

MAIN OUTCOME MEASURES

Prevalence of C trachomatis infection in women aged 18-35 on the basis of each test; sensitivity and specificity of both tests in this population.

RESULTS

Prevalence of confirmed infection was 2.6% (95% confidence interval 1.6% to 3.6%) in all women. Prevalence on the basis of enzyme immunoassay was 1.6% (0.8% to 2.7%), with a sensitivity of 60% and a specificity of 100%. Prevalence on the basis of ligase chain reaction was 2.5% (1.5% to 3.9%), with 90% sensitivity and 99.8% specificity. Screening all women aged < or = 25 and all women who had had two or more partners in the past year would have detected 87% (20/23) of infections.

CONCLUSION

Ligase chain reaction on urine samples performs at least as well as enzyme immunoassay on cervical specimens in this low prevalence population. It offers potential as a non-invasive screening tool. A simple selective screening strategy might be appropriate and would be able to detect most cases of infection. However, a rigorous economic evaluation of possible screening strategies is needed first.

Low-dose diethyldithiocarbamate attenuates the hepatotoxicity of 1,3-dichloro-2-propanol and selectively inhibits CYP2E1 activity in the rat

The effect of low doses of diethyldithiocarbamate (DEDC) on hepatic cytochrome P450-dependent enzyme activity and 1,3-dichloro-2-propanol (DCP) hepatotoxicity in the rat have been investigated. DEDC at a dose of 5 mg/kg selectively inhibited enzyme markers for CYP2E1 activity, and provided substantial protection against DCP hepatotoxicity. At a higher dose (25 mg/kg), DEDC also inhibited an enzyme marker for CYP1A2 activity and provided complete protection against DCP hepatotoxicity. It is concluded: (a) that DEDC at a dose of 5 mg/kg is a selective CYP2E1 inhibitor in the rat in vivo; and (b) that DCP hepatotoxicity is mediated principally by CYP2E1, with a possible contribution from CYP1A2.

Comparison of MRC-5 and primary rabbit kidney cells for the detection of herpes simplex virus

OBJECTIVE

To compare MRC-5 and primary rabbit kidney (PRK) cells to either cell monolayer alone for the recovery of herpes simplex virus (HSV).

DESIGN

A total of 2476 specimens received for HSV culture during a 3-year period were cultured on MRC-5 and PRK cells. Detection rates and the time to first detection were determined for each cell type used. A cost analysis was also performed for the isolation and identification of HSV using both cell types, the MRC-5 cell line alone, and PRK cell culture alone.

SETTING

Large, urban, tertiary-care, university-affiliated hospital.

RESULTS

Of the 2476 specimens cultured for HSV, 535 (21.6%) were positive. The MRC-5 cell line detected 531 (99.3%), and the PRK cell culture detected 522 (97.6%) of the positive specimens. Thirteen HSV isolates were detected only in MRC-5 cells, and four were isolated only in PRK cells. Approximately 44% of the cultures were positive by day 1, 84% by day 2, and 98% by day 3, regardless of the cell type used. The total cost per culture was comparable for MRC-5 and PRK cells.

CONCLUSIONS

There was no difference in the sensitivity or time to detection of HSV between PRK and MRC-5 cells either alone or in combination. Either cell type alone represents an efficient, cost-effective method for the isolation of HSV.

Kit helps physicians, women work together to weigh HRT risks, benefits

The Ottawa Health Decision Centre is developing a line of decision AIDS to make it easier for physicians to discuss potential therapies with patients. The first kit, Making choices: hormones after menopause, helps women weigh the risks and benefits of hormone replacement therapy.

Developmental aspects of sleep and breathing

The developmental aspects of sleep and breathing are rarely treated as one subject. This report attempts to link the fields of sleep research and developmental pulmonology in a comprehensive description of development and control of sleep and breathing from gestation to adulthood. Unfortunately, much of the investigation in this area is basic physiology and was done some time ago. Although this subject matter need not be updated, some of these references are older; however, this may be new information for the pulmonologist. The second part of this report details the pathophysiologic mechanisms behind the development of sleep-disordered breathing in children and adults. In fact, developmental abnormalities that occur in childhood may recrudesce in adulthood. We conclude with a discussion of the familial and genetic aspects of sleep-disordered breathing and consider the place of sudden infant death syndrome in the spectrum of these disorders.

Making information accessible: developing plain English discharge instructions

Discharge education has always been an important role for nurses working in acute care contexts. With the advent of case mix funding and subsequent trends towards early discharge from hospital, this educational role is assuming increasing importance. This paper addresses one aspect of a participatory action research study where a group of nurses, working in a paediatric orthopaedic ward, explored their discharge education practices and resources. The seemingly large number of post-discharge telephone queries received from parents of children treated on the ward prompted these nurses to question whether their discharge teaching practices were effective. Data collected on these telephone queries identified parental concerns regarding the care of their child at home in a plaster. This finding prompted group members to explore the ways that written information relating to care of the plaster at home might be implicated in the situation. An analysis of an existing 'home cast care' discharge instruction sheet raised issues concerning the content and language used in such resources. The paper describes the subsequent development of a plain English 'plaster care' discharge instruction sheet and argues the importance of using plain English in such resources.

Multivariate analyses of prognostic factors associated with hematopoietic recovery in autograft patients with different sources of progenitor cells. A GATMO experience. Argintine Group of Bone Marrow Transplant

OBJECTIVE

To evaluate in a multivariate analysis the prognostic factors associated with hematopoietic recovery and the supportive care requirements after autotransplant of progenitor cells (PC) from various sources: bone marrow (BMPC), BMPC & peripheral blood (PBPC), and PBPC alone.

PATIENTS AND METHODS

A total of 570 patients with hematological malignancies and solid tumors underwent high-dose therapy followed by autotransplant. PBPC were obtained after mobilization with chemotherapy and/or cytokines. One-hundred five patients received BMPC, 217 received BMPC & PBPC and 248 PBPC alone; all of the patients received G-CSF or GM-CSF after infusion.

RESULTS

In a multivariate analysis the recovery of neutrophils was adversely associated with low numbers of nucleated cells infused (P < 0.13), bone marrow progenitor cell source, and diagnosis of multiple myeloma and acute leukemia (P < 0.001). The factors that adversely affected platelet recovery were low number of nucleated cells and diagnosis of multiple myeloma and acute leukemia (P < 0.001).

CONCLUSIONS

We conclude that BMPC adversely affect neutrophil recovery while low numbers of nucleated cells and diagnosis of multiple myeloma and acute leukemia adversely affect both neutrophil and platelet recovery.