Epidemiology of an outbreak of drug-resistant tuberculosis in the U.K. using restriction fragment length polymorphism

1. Drug-resistant tuberculosis is a growing health care problem. When a series of cases occur, it is essential to know if patients with multidrug-resistant disease represent one or a number of separate outbreaks. 2. The epidemiology of an outbreak of isoniazid- and streptomycin-resistant tuberculosis in Blackburn was studied by restriction fragment length polymorphism using a probe for the IS6110 DNA sequence. 3. Mycobacterium tuberculosis from four cases of isoniazid- and streptomycin-resistant disease had an identical restriction fragment length polymorphism pattern. This pattern was not shared by drug-sensitive isolates of M. tuberculosis obtained from Blackburn (n = 8) or London (n = 13) or a M. tuberculosis isolate from a fifth Blackburn case which was resistant to isoniazid alone. 4. This methodology confirmed that all four cases of isoniazid- and streptomycin-resistant disease were part of a single epidemiologically related outbreak of drug-resistant disease. This study demonstrates how the epidemiology of an outbreak of multidrug-resistant tuberculosis in the U.K. can be confirmed by restriction fragment length polymorphism.

Evidence for a Th1-like bronchoalveolar T-cell subset and predominance of interferon-gamma gene activation in pulmonary tuberculosis

Mycobacterium-specific human helper T-cell clones produce a Th1 pattern of cytokines in vitro: interferon-gamma (IFN-gamma) and interleukin-2 (IL-2), but little or no IL-4 or IL-5. To test the hypothesis that a similar Th1-like pattern of cytokine gene expression occurs in vivo in pulmonary tuberculosis we used in situ hybridization to detect cytokine mRNA expression by bronchoalveolar lavage cells from nine patients with microbiologically confirmed tuberculosis and nine control subjects. Because IFN-gamma may also originate from alveolar macrophages, simultaneous immunocytochemistry and in situ hybridization was applied to determine whether cytokine mRNA was localized to bronchoalveolar macrophages in addition to T-lymphocytes. When samples from patients with tuberculosis and control subjects were compared, there was a significant increase in numbers of IFN-gamma mRNA-positive BAL cells per 1,000 among patients with tuberculosis (p < 0.01). Differences between the two groups in the proportions of cells expressing IL-2, IL-4, or IL-5 mRNA were not significant. Expression of IFN-gamma mRNA by macrophages was detected (median, 14.3% of IFN-gamma mRNA-positive BAL cells). However, the majority of IFN-gamma mRNA expressing BAL cells were T-lymphocytes (median, 80.7%). Activation of Th1-like bronchoalveolar T-lymphocytes, together with production of IFN-gamma by alveolar macrophages, may contribute to the local cellular immune response in pulmonary tuberculosis.

A technique for the isolation and purification of viable mucosal mast cells/globule leukocytes from the small intestine of parasitised sheep

Romney sheep, 1-2 years old, immunized by at least three anthelmintic abbreviated infections of 80-100,000 Trichostrongylus colubriformis larvae usually produced high numbers of intestinal mucosal mast cells/globule leukocytes (MMC/GLs). In isolating these cells, the importance of maintaining the intestine at 37 degrees C, removal of mucus with dithiothreitol, enzymatic dispersion and careful in vitro handling procedures for maximising cell viability are emphasised. The MMC/GLs were separated from most contaminant cells by using a Percoll discontinuous gradient. MMC/GLs collected at the 60/100% Percoll interface were passed through a complement coated nylon wood column to remove the contaminating eosinophils. Viable MMC/GLs were able to grow in vitro in the presence of Concanavalin A and survive in culture for up to 30 days. The MMC/GLs were readily identified by ultraviolet light microscopy after staining with auramine O.

A survey of symptoms in hospice patients in Singapore

A descriptive study was done on patients referred to a hospice home care service in Singapore. The demographic profile, type of disease, presenting symptoms and performance status were noted. Particular attention was paid to the incidence of pain and types of analgesics used. The patients referred were representative of the population at large, as was their incidence of cancer. Eastern Cooperative Oncology Group (ECOG) performance status was poor (ECOG 3 or 4) in 93 (93%) of the patients referred, indicative of the lateness of referral in many cases. The number of symptoms per patient averaged 5.8, and pattern of symptoms were similar to those of comparable groups of patients in other parts of the world. Pain was present in 82 (82%) patients and controlled only in 22 (22%) of these at presentation. Strong opioids had been prescribed for 51 (51%) patients. In these, oral morphine mixture was incorrectly prescribed in 17 (47%) out of 36 cases. Education in palliative care is needed so that patients are referred to palliative care services appropriately. Though there is some indication of improvement, medical education in pain management continues to be necessary, particularly in the correct prescription of morphine.

Evolution of a hospice home care service in Singapore

The hospice movement in Singapore was started in 1985 when St Joseph's Home opened its doors to terminally ill patients by setting aside 16 beds for hospice care. A newspaper article about this work brought together a group of volunteers who started a hospice home care service under the auspices of the Singapore Cancer Society in 1987. This service was originally entirely staffed by volunteers until a charitable foundation made possible the employment of a nurse coordinator in 1988. Nearly two years later, in December 1989, the Hospice Care Association, a new charitable organization specifically devoted to the promotion and provision of hospice care, was formed. With charitable funding from the community, the new organization built on the experience of the volunteer-run hospice home care service and developed it into one in which professionals provide most of the care, supported by volunteers. Full-time staff were responsible for the day-to-day running of the service, providing for reliability and setting and maintaining of standards, while the role of volunteers changed to that of supporting, supplementing and enhancing the quality of the care given to patients. This paper chronicles the evolution of this service and describes its present functioning.

Pharmacological modulation of c-fos mRNA expression in the HL60 and U937 cell lines

A variety of drugs known to act via increasing intracellular cAMP are used in the treatment of asthma. In this study we asked whether anti-asthma drugs are capable of altering gene activation. We determined whether phosphodiesterase inhibitors, either alone or in combination with adrenoceptor agonists, were able to alter the abundance of mRNA of the cAMP responsive gene c-fos in the cell-lines HL60 and U937. Incubation of cells with phosphodiesterase inhibitors aminophylline, theophylline or pentoxyphylline all resulted in an increase in c-fos mRNA. Further upregulation of c-fos mRNA abundance was observed when the cells were stimulated with the combination of aminophylline and adrenoceptor agonists with beta 2-agonist activity. These increases in c-fos mRNA were accompanied by increases in intracellular concentration of cAMP. These data suggest that in these in vitro models, combinations of beta 2-adrenoceptor agonists and phosphodiesterase inhibitors can increase intracellular cAMP and affect gene activation.

Up-regulation of alveolar macrophage platelet-derived growth factor-B (PDGF-B) mRNA by interferon-gamma from Mycobacterium tuberculosis antigen (PPD)-stimulated lymphocytes

Macrophage production of PDGF-B is believed to be important in the pathogenesis of diseases where chronic lung inflammation develops into fibrosis. Since tuberculosis is characterized by chronic inflammation and tissue fibrosis, we asked if lymphokines from lymphocytes stimulated by the Mycobacterium tuberculosis antigen PPD, contained factors capable of increasing human alveolar macrophage PDGF-B mRNA. Supernatants from both phytohaemagglutinin (PHA)- and purified protein derivative (PPD)-stimulated lymphocytes, when added to macrophages, induced an increase in the mRNA of PDGF-B, but not transforming growth factor-beta (TGF-beta). When lymphocytes from contacts of patients with tuberculosis, patients with tuberculosis, and normal subjects were compared following PPD stimulation, the lymphocytes from the contacts had the greatest proliferation response, the greatest production of interferon-gamma (IFN-gamma), and their lymphokines induced the greatest increase in PDGF-B mRNA in macrophages. Recombinant human IFN-gamma reproduced this ability of lymphokines to increase macrophage PDGF-B mRNA. Finally, the increase in macrophage PDGF-B mRNA following incubation with supernatants from PPD-stimulated lymphocytes was shown to be due to IFN-gamma, when the increase in macrophage PDGF-B mRNA was prevented by addition of anti-human IFN-gamma antibody to the lymphocyte supernatant. This study indicated that antigen-stimulated lymphocytes released IFN-gamma, which in turn resulted in an increase in PDGF-B mRNA in alveolar macrophages. Such a mechanism provides a link between the DTH response and the first stages of a fibrotic reaction, and may offer an explanation for the progression of chronic inflammation to fibrosis, as occurs in the lungs of patients with untreated pulmonary tuberculosis.

Serial pulmonary function tests in the diagnosis of P. carinii pneumonia

The predictive value of serial versus isolated measurements of transfer factor for carbon monoxide (TLCO) in the diagnosis of pneumocystis carinii pneumonia (PCP) in a cohort of 474 HIV-1 seropositive patients, with all stages of HIV disease, was evaluated. Two groups of patients were studied, one group with serial lung function measurements (Group 1) and another with only a single set of measurements (Group 2). During the study period 118 patients performing serial tests developed a respiratory illness of which 58 were performing monthly and 60 three monthly measurements of lung function (Group 1). In 36 patients from Group 1, where PCP was diagnosed, monthly lung function tests showed a decrease in TLCO from 68% (+/- 3.2) (SEM), (8 weeks prior to illness), to 44% (+/- 2.5) predicted normal at presentation, whereas in 22 patients who did not have PCP, TLCO fell from 71% (+/- 4.5) to 57% (+/- 3.1). TLCO was thus reduced to lower values in these with PCP than in those without PCP (p < 0.05). A fall of TLCO of 5% from initial values when used as predictive for presence of PCP had a sensitivity of 75% and a specificty of 28% (positive predictive value 56%; negative predictive value 48%). TLCO was < 70% predicted in 72/78 patients with PCP who performed only single lung function tests (Group 2), which gave a sensitivity of 92% and a specificity of 71% as a diagnostic test for PCP when compared with the cohort as a whole. The positive predictive value was 34%, negative predictive value was 98%.(ABSTRACT TRUNCATED AT 250 WORDS)

Serial pulmonary function tests in the diagnosis of P. carinii pneumonia

The predictive value of serial versus isolated measurements of transfer factor for carbon monoxide (TLCO) in the diagnosis of pneumocystis carinii pneumonia (PCP) in a cohort of 474 HIV-1 seropositive patients, with all stages of HIV disease, was evaluated. Two groups of patients were studied, one group with serial lung function measurements (Group 1) and another with only a single set of measurements (Group 2). During the study period 118 patients performing serial tests developed a respiratory illness of which 58 were performing monthly and 60 three monthly measurements of lung function (Group 1). In 36 patients from Group 1, where PCP was diagnosed, monthly lung function tests showed a decrease in TLCO from 68% (+/- 3.2) (SEM), (8 weeks prior to illness), to 44% (+/- 2.5) predicted normal at presentation, whereas in 22 patients who did not have PCP, TLCO fell from 71% (+/- 4.5) to 57% (+/- 3.1). TLCO was thus reduced to lower values in these with PCP than in those without PCP (p < 0.05). A fall of TLCO of 5% from initial values when used as predictive for presence of PCP had a sensitivity of 75% and a specificty of 28% (positive predictive value 56%; negative predictive value 48%). TLCO was < 70% predicted in 72/78 patients with PCP who performed only single lung function tests (Group 2), which gave a sensitivity of 92% and a specificity of 71% as a diagnostic test for PCP when compared with the cohort as a whole. The positive predictive value was 34%, negative predictive value was 98%.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of environmental support on implicit and explicit memory in younger and older adults

The study addressed 2 major issues: whether there are age differences on an implicit word-stem-completion task and whether age differences on both implicit and explicit memory would decrease with increased environmental support. A total of 287 Ss were presented with words in an incidental learning task with structural or semantic processing. Following 2 filler tasks, Ss received an implicit or an explicit word-stem-completion task. The number of letters in the stem varied from 2 to 4. Results yielded an Age x Memory Task dissociation such that there were large age differences on the explicit task and no age difference on the implicit task, regardless of whether Ss aware of the memory test were included or excluded. There was no evidence that environmental support improved older adults' performance more than that of younger adults on either memory task.

Coping effectiveness in nursing home residents. The role of control

The purpose of this study was to investigate the role of perceived control in the selection and effectiveness of coping strategies used by nursing home residents. A path analysis of a model of coping effectiveness was conducted using a cluster sample of 100 nursing home residents. Respondents were assisted in completing the Importance, Locus, and Range of Activities Checklist, the Jalowiec Coping Scale, two self-anchoring ladders measuring coping effectiveness, and an item measuring perceived health. Mental status was measured with the Pfeiffer Short Portable Mental Status Questionnaire. Results demonstrated that mental status and functional ability were positively related to perceived control (p < .01). Perceived health and the use of secondary control (e.g., prayer, getting help from family, and depending on others) were the only two variables positively influencing coping effectiveness (p < .01 and p < .05, respectively). Longitudinal studies are recommended to investigate these relationships as they evolve.

Modulation of platelet-derived growth factor B mRNA abundance in macrophages by colchicine and dibutyryl-cAMP

Macrophage production of growth factors for fibroblasts, in particular platelet-derived growth factor B [PDGF(B)] and transforming growth factor-beta (TGF-beta), is thought to be central to the pathogenesis of pulmonary fibrosis. In a search for anti-inflammatory agents that might prevent this process, we asked whether colchicine might modulate the abundance of PDGF(B) and TGF-beta mRNA, as well as the mRNA of early growth response gene 2 (EGR2), in human macrophages. Colchicine caused a dose- and time-dependent increase in PDGF(B), but not TGF-beta or EGR2, mRNA in human macrophages derived from culture of peripheral blood monocytes. Similarly, colchicine caused an increase in PDGF(B) mRNA in human alveolar macrophages obtained from normal volunteers. Colchicine also caused an increase in PDGF(B) protein production by macrophages, as determined by enzyme-linked immunosorbent assay. Interferon-gamma further increased the PDGF(B) mRNA abundance in human alveolar but not monocyte-derived macrophages. The effect of coincubation with dibutyryl-cAMP (dBcAMP) was assessed in an attempt to prevent the colchicine-induced increase in PDGF(B) mRNA. dBcAMP alone resulted in no increase in PDGF(B) mRNA or alteration in TGF-beta mRNA but resulted in a reduction in EGR2 mRNA. When added with colchicine, dBcAMP completely abrogated the colchicine-induced increase in PDGF(B) mRNA but had little effect on TGF-beta mRNA. These data, showing that colchicine increased macrophage PDGF(B) mRNA in human macrophages and that this was prevented by coincubation with dBcAMP, lead us to speculate that colchicine may not be helpful in preventing the contribution of macrophage PDGF(B) gene activation to the pathogenesis of lung fibrosis. However, this effect of colchicine may be prevented by increasing intracellular cAMP in macrophages.

Pulmonary function in human immunodeficiency virus infection. A prospective 18-month study of serial lung function in 474 patients

To investigate the development of a reduced DLCO in patients with HIV-related disease, we studied 474 HIV-seropositive patients and performed serial lung function measurements over 18 months. The mean values of DLCO at presentation were lower in patients with more advanced HIV disease compared with asymptomatic HIV-seropositive patients (DLCO 88% of predicted). When compared with the DLCO in asymptomatic HIV-seropositive patients, the DLCO had reduced values in patients with persistent generalized lymphadenopathy (PGL) (82% of predicted, p less than 0.05), acquired deficiency syndrome-related complex (ARC) (73% predicted, p less than 0.001), nonpulmonary Kaposi's sarcoma (KS) (72% of predicted, p less than 0.001), nonpulmonary complications of AIDS excluding KS (73% of predicted, p less than 0.001), pulmonary KS (63% of predicted, p less than 0.001), pulmonary mycobacterial infection (68% of predicted, p less than 0.05), pyogenic infection (70%, p less than 0.05), acute Pneumocystis carinii pneumonia (PCP; 49%, p less than 0.001), and following recovery from PCP (71%, p less than 0.001). Serial lung function measurements over 18 months revealed no change in DLCO within any patient group, and in particular there was no tendency for a gradual decline. Clinical deterioration due to the development of PCP was associated with a reduction in DLCO. Conversely, in patients recovering from PCP, there was a partial improvement in DLCO over 3 months. Zidovudine (AZT) use did not affect DLCO within any diagnostic group or the recovery in DLCO following PCP. However, cigarette smoking was associated with further reductions in DLCO in all patient groups and with an impaired recovery of DLCO following acute PCP.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of polymerase chain reaction amplification of two mycobacterial DNA sequences, IS6110 and the 65kDa antigen gene, in the diagnosis of tuberculosis

BACKGROUND

Knowledge of the sequences of mycobacterial genes and the availability of DNA amplification techniques have raised the possibility that identification of mycobacterial DNA may offer a rapid and specific diagnostic test for tuberculosis. The correlation between the presence of Mycobacterium tuberculosis DNA and clinical tuberculosis, however, is not known. This study compared the results of polymerase chain reaction amplification of two M tuberculosis DNA sequences, IS6110 and the gene encoding the 65kDa heat shock protein (65kDa Ag), from sputum, bronchoscopy washings, and bronchoalveolar lavage fluid and related these findings to the presence of active and past tuberculosis.

METHODS

Highly specific primers were used for amplification of IS6110 and 65kDa Ag DNA. Analysis was performed on one or more samples from 87 patients.

RESULTS

IS6110 DNA was identified in samples from all six patients with active tuberculosis, from 15 to 18 patients with past tuberculosis, from five of nine contacts of patients with tuberculosis, and from nine of 54 patients with lung disease unrelated to tuberculosis. The 65kDa Ag DNA was identified in samples from all patients with active and past tuberculosis, from contacts of patients with tuberculosis, and from 14 of 42 patients with non-tuberculous lung diseases.

CONCLUSION

These data suggest that the presence of IS6110 DNA correlates more closely with a tuberculosis related diagnosis than that of 65kDa Ag DNA and that both DNAs are found in most subjects with past tuberculosis or contacts of patients with tuberculosis. This may limit the clinical usefulness of these tests.

Dexamethasone-induced increase in platelet-derived growth factor (B) mRNA in human alveolar macrophages and myelomonocytic HL60 macrophage-like cells

Platelet-derived growth factor (B) (PDGF(B)) from alveolar macrophages is thought to play a central role in orchestrating the fibrotic response. Because corticosteroids are widely used in the treatment of patients with lung fibrosis, we asked whether corticosteroids modulated PDGF(B) gene activation in macrophages. PDGF(B) mRNA in alveolar macrophages obtained from smokers was increased after culture in the presence of dexamethasone (P less than 0.05), interferon-gamma (IFN-gamma) (P less than 0.05), or both in combination (P less than 0.05). Dexamethasone did not alter the abundance of mRNA encoding transforming growth factor-beta (TGF-beta), but did decrease the mRNA of early growth response gene 2 (EGR2). These initial experiments required large numbers of cells and thus were performed on macrophages from smokers. The results were reproduced when PDGF(B) mRNA abundance in macrophages from healthy nonsmoking volunteers was measured by the reverse-transcriptase polymerase chain reaction (RT-PCR). There was an increase in PDGF(B) mRNA in macrophages from nonsmokers after stimulation with dexamethasone alone (P less than 0.05) or in combination with IFN-gamma (P less than 0.05). To provide adequate cell numbers for kinetic and dose-response studies, the in vitro model of phorbol ester (TPA)-induced differentiation of HL60 cells to macrophage-like cells was used. In these cells, dexamethasone caused a 20-fold increase in the abundance of PDGF(B) mRNA, which was concentration and time dependent but not associated with changes in TGF-beta or EGR2 mRNA. This study suggests that in addition to their anti-inflammatory effects, corticosteroids may also increase the abundance of PDGF(B) mRNA.

Effect of environmental support on implicit and explicit memory in younger and older adults

The study addressed 2 major issues: whether there are age differences on an implicit word-stem-completion task and whether age differences on both implicit and explicit memory would decrease with increased environmental support. A total of 287 Ss were presented with words in an incidental learning task with structural or semantic processing. Following 2 filler tasks, Ss received an implicit or an explicit word-stem-completion task. The number of letters in the stem varied from 2 to 4. Results yielded an Age x Memory Task dissociation such that there were large age differences on the explicit task and no age difference on the implicit task, regardless of whether Ss aware of the memory test were included or excluded. There was no evidence that environmental support improved older adults' performance more than that of younger adults on either memory task.

Age-related increases in the effects of automatic semantic activation

Automatic semantic activation was assessed in a version of the flanker task, in which nominally irrelevant words were presented above and below a target word. The category membership of the flanking word was consistent, inconsistent, or neutral with respect to the target word. Older adults showed greater inhibition and equivalent facilitation in the time taken to classify the target words than did younger adults in 2 of 3 experiments, in contrast to previous findings. The present results are generally consistent with 3 dominant perspectives in cognitive aging: the complexity hypothesis, environmental support, and the inhibition-deficit view. Manipulation of the overall magnitude of the flanker effect produced results most consistent with the inhibition-deficit view that older adults are less able to inhibit automatic processes than are younger adults. Some problems with the inhibition-deficit view are also discussed.

Effects of adult age on structural and operational capacities in working memory

Eight experiments were conducted in which young adults and older adults were asked to report the latest value of 1 of several continuously changing numeric or spatial variables. Accuracy of reporting the current value of the target variable was lower with increases in the number of potentially relevant variables and with increases in the number of required processing operations. Young and older adults exhibited similar effects of the number of potentially relevant variables (hypothesized to be sensitive to the structural capacity of working memory) and of the number of required processing operations (hypothesized to be sensitive to the operational capacity of working memory), but older adults were generally less accurate than young adults.

Age-related increases in the effects of automatic semantic activation

Automatic semantic activation was assessed in a version of the flanker task, in which nominally irrelevant words were presented above and below a target word. The category membership of the flanking word was consistent, inconsistent, or neutral with respect to the target word. Older adults showed greater inhibition and equivalent facilitation in the time taken to classify the target words than did younger adults in 2 of 3 experiments, in contrast to previous findings. The present results are generally consistent with 3 dominant perspectives in cognitive aging: the complexity hypothesis, environmental support, and the inhibition-deficit view. Manipulation of the overall magnitude of the flanker effect produced results most consistent with the inhibition-deficit view that older adults are less able to inhibit automatic processes than are younger adults. Some problems with the inhibition-deficit view are also discussed.

Pathogenesis of pulmonary fibrosis in interstitial lung disease. Alveolar macrophage PDGF(B) gene activation and up-regulation by interferon gamma

Alveolar macrophages are believed to be central in orchestrating the fibrotic response in interstitial lung disease (ILD). To test the hypothesis that macrophages from patients with ILD were dedicated to growth factor production and that this was independent of other indices of macrophage activation, we measured the mRNA of the B chain of PDGF and TGF-beta, as well as HLA-DR-alpha in alveolar macrophages from patients with ILD and from normal control subjects. When alveolar macrophages were examined immediately after lavage, cells from patients with ILD had increased PDGF(B) but similar TGF-beta and HLA-DR-alpha mRNA when compared with control subjects. Discoordinate regulation of these genes was observed when alveolar macrophage PDGF(B) mRNA increased while TGF-beta and HLA-DR-alpha mRNA decreased after culture for 24 h. This response was not disease-related as these changes were similar in cells from patients with ILD and from control subjects. Because a lymphocytic alveolitis is present in many cases of ILD, we asked whether interferon gamma (IFN-gamma) modulated the activation of these genes. In both the patients and the control subjects, PDGF(B) and HLA-DR-alpha, but not TGF-beta, mRNA were increased after incubation with IFN-gamma. These results indicate that PDGF(B) mRNA may be increased in alveolar macrophages in ILD and that PDGF(B), TGF-beta, and HLA-DR-alpha are independently regulated genes in alveolar macrophages, but that IFN-gamma increases both PDGF(B) and HLA-DR-alpha mRNA. We speculate that IFN-gamma induced PDGF(B) gene activation may be an important mechanism by which lymphocytes promote pulmonary fibrosis.

Effects of adult age on structural and operational capacities in working memory

Eight experiments were conducted in which young adults and older adults were asked to report the latest value of 1 of several continuously changing numeric or spatial variables. Accuracy of reporting the current value of the target variable was lower with increases in the number of potentially relevant variables and with increases in the number of required processing operations. Young and older adults exhibited similar effects of the number of potentially relevant variables (hypothesized to be sensitive to the structural capacity of working memory) and of the number of required processing operations (hypothesized to be sensitive to the operational capacity of working memory), but older adults were generally less accurate than young adults.

Adherence-dependent increase in human monocyte PDGF(B) mRNA is associated with increases in c-fos, c-jun, and EGR2 mRNA

Adherence is an important initial step in the transition of a circulating monocyte to a tissue macrophage. This differentiation is accompanied by an augmented capacity to generate growth factors. We hypothesized that adherence itself might be an important trigger for a sequence of gene activation culminating in cells with increased mRNA encoding profibrotic growth factors such as platelet-derived growth factor B subunit (PDGF[B]) and transforming growth factor-beta (TGF-beta). After in vitro adherence, human monocytes had a biphasic increase in PDGF(B) mRNA with peaks at 6 h and 13 d. No increase in TGF-beta mRNA was observed. The 6-h increase in PDGF(B) mRNA was adherence dependent, and in addition, was abrogated when the cytoskeletal integrity was compromised by cytochalasin D. The 6-h increase in PDGF(B) mRNA was unaltered by adherence in the presence of the monocyte stimulus lipopolysaccharide. Adherence to either fibronectin or collagen-coated plastic had little consistent effect on PDGF(B) mRNA accumulation. The increased PDGF(B) mRNA observed in adherent monocytes was accompanied by increases in mRNAs of the early growth response genes c-fos (maximal at 20 min), c-jun, and EGR2 (maximal at 6-24 h). The increase in c-jun and EGR2, but not c-fos, mRNA was also abrogated by cytochalasin D. These observations suggest that adherence results in increases of c-fos, c-jun, EGR2, and PDGF(B) mRNA. In addition, the increases in c-jun, EGR2, and PDGF(B) may depend on cytoskeletal rearrangement. Modulation of these events at the time of adherence offers a mechanism by which differential priming of the cells may be accomplished.

Age differences in components of metamemory

Young adults (N = 58) and older adults (N = 55) answered 30 questions extracted from three dimensions of the Metamemory in Adulthood (MIA) questionnaire: Capacity, Task and Strategy. The older participants scored significantly lower on the Capacity dimension, indicating that they report having greater difficulty in everyday memory situations. There was no age difference on any item in the Task dimension; both groups were equally knowledgeable about memory task demands. Responses to Strategy items varied with type of strategy: younger adults were more likely than older adults to report the use of encoding strategies, while older adults reported significantly more use of strategies which involved planning and organization. A further group of employed young adults (N = 26) was added to clarify the respective roles of aging and environmental demands on strategy use. The findings suggest that both changes in lifestyle and the effects of aging per se play some part in the use of particular memory strategies.

Echinococcus granulosus: ultrastructure of epithelial changes during the first 8 days of metacestode development in vitro

The epithelium of artificially hatched and activated oncospheres of E. granulosus was studied ultrastructurally over the first 8 days of metacestode development in vitro. Within 4 h of activation, the epithelium was transformed from a thin cytoplasmic layer into a much wider layer packed with penetration gland granules and containing mitochondria and Golgi apparatus. Microvilli were extended from the outer plasma membrane and the basal lamina on the inner epithelial surface virtually disappeared. Microvilli increased in number and length over the first 24 h of development while granules in both the epithelium and penetration gland decreased in number. The granules appear to be involved in microvilli formation. After 3 days of development, the first lamination resolved ultrastructurally as shortened microvilli and some microtriches extending from the epithelium surrounded by an electron-dense microfibrillate material containing sloughed microvilli. By 6 days post-activation, no microvilli remained and only double-walled truncated microtriches extended from the epithelium. The microfibrillate material had become more electron-dense and was closer to the epithelium than at day 1. Within 8 days of metacestode development, a second lamination had developed. Both microfibrillate and particulate material of a greater electron density than the first lamination was added to the microthrix side of the first lamination.

Myoclonus associated with treatment with high doses of morphine: the role of supplemental drugs

OBJECTIVE

To estimate the prevalence of important side effects in patients with malignant disease who were receiving high doses of morphine as part of their palliative treatment.

DESIGN

Data on patients were collected over 12 months.

SETTING

Two palliative care units in Western Australia.

PATIENTS

19 Patients with malignant disease who were receiving morphine either subcutaneously or orally as the main analgesic. 10 Patients receiving a total daily dose of morphine of at least 500 mg orally or 250 mg parenterally were enrolled in the study. The other 9 patients were enrolled after an important problem thought to be related to the morphine had been identified. All of the patients were taking drugs to supplement the treatment.

INTERVENTIONS

The dose of morphine or route of administration, or both, was changed in three patients.

MAIN OUTCOME MEASURE

Determination of the prevalence of side effects in the patients. Assessment of the relation of any side effects with the supplemental drugs taken by the patients.

MAIN RESULTS

Plasma morphine and electrolyte concentrations were measured and a full history taken for each patient. Thirteen of the 19 patients had an important side effect; 12 of them had myoclonus and one had hyperalgesia of the skin. Plasma morphine concentrations were similar in patients with and without myoclonus, ranging from 158 to 3465 nmol/l and 39 to 2821 nmol/l respectively. Eight of the patients with side effects were taking an antipsychotic drug concurrently compared with none of those without side effects. A greater proportion of patients with side effects were taking the antinauseant drug thiethylperazine (6/13 v 2/6) and at least one non-steroidal anti-inflammatory drug (10/13 v 2/6), whereas a smaller proportion were taking a glucocorticosteroid (3/13 v 4/6). The estimated prevalence of important side effects in the total population of patients receiving palliative treatment in the two units was 2.7-3.6%.

CONCLUSIONS

Myoclonus as a side effect of treatment with morphine is more likely to occur in patients taking antidepressant or antipsychotic drugs as antiemetics or as adjuvant agents or non-steroidal anti-inflammatory drugs for additional analgesia. If a patient develops myoclonus the best approach may be to change the supplemental treatment.

Age differences in predictions and performance on a cued recall task

The notion that older adults fail to use optimal encoding strategies in memory tasks because of a deficit in memory monitoring was examined in a cued recall task. Participants were given different types of descriptors (initial letters, rhyme, category) for each word during encoding, and these descriptors were later given as cues at recall. Participants also predicted the likelihood of recalling each item. Age differences were found in recall performance, but there were no age differences in average predictions. However, the prediction ratings given by younger adults showed a greater difference between words recalled and words not recalled in the subsequent test than did the ratings of the older adults. Differences in recall associated with different types of processing were predicted poorly by all of the participants, but the relative recallability of specific words was well assessed by both age groups. We concluded that a memory monitoring deficit is not likely to be responsible for age differences in memory.

Age differences in predictions and performance on a cued recall task

The notion that older adults fail to use optimal encoding strategies in memory tasks because of a deficit in memory monitoring was examined in a cued recall task. Participants were given different types of descriptors (initial letters, rhyme, category) for each word during encoding, and these descriptors were later given as cues at recall. Participants also predicted the likelihood of recalling each item. Age differences were found in recall performance, but there were no age differences in average predictions. However, the prediction ratings given by younger adults showed a greater difference between words recalled and words not recalled in the subsequent test than did the ratings of the older adults. Differences in recall associated with different types of processing were predicted poorly by all of the participants, but the relative recallability of specific words was well assessed by both age groups. We concluded that a memory monitoring deficit is not likely to be responsible for age differences in memory.

Leukotriene C4 generation from human eosinophils stimulated with IgG-Aspergillus fumigatus antigen immune complexes

Sepharose beads coated with IgG stimulate eosinophils to produce leukotriene C4 (LTC4). This observation has been extended with specific immobilized IgG/antigen immune complexes to elicit mediator generation. An extract of Aspergillus fumigatus was covalently coupled to Sepharose beads and incubated with the IgG fraction of immune serum from patients with allergic bronchopulmonary aspergillosis. These beads elicited generation of 7.72 +/- 1.7 pmol of LTC4 immunoreactive material (n = 5) from 1 X 10(6) normal eosinophils of greater than 86% purity, and significantly less LTC4 (0.73 +/- 0.19 pmol per 10(6) cells; n = 3) was produced by eosinophils after incubation with beads treated with IgG from normal nonimmune serum. The maximum antibody-dependent release achieved represented approximately 20% of that induced by the calcium ionophore (A23187). LTC4 was measured by radioimmunoassay and validated by reverse-phase high-performance liquid chromatography. The amount of LTC4 generated was dependent on the concentration of A. fumigatus-specific IgG, and mediator release was completely abolished by prior adsorption of the IgG fraction onto Sepharose-protein A (Staphylococcus aureus). Grass pollen-specific IgG antibody/antigen complexes, in combination with Sepharose beads, also triggered generation of LTC4 immunoreactive material. There was no evidence to suggest that IgE/A. fumigatus immune complexes triggered LTC4 generation, although IgE myeloma protein, in association with Sepharose beads, was a weak stimulus. The efficacy of the IgG immune complex-dependent stimulation of eosinophils suggests a possible physiologic mechanism whereby these cells could participate in the inflammatory changes associated with allergic bronchopulmonary aspergillosis and similar allergic disorders.

Lung function abnormalities in patients infected with the human immunodeficiency virus with and without overt pneumonitis

Pulmonary function was measured in 169 male patients seropositive for the human immunodeficiency virus (HIV). The transfer factor for carbon monoxide (TLCO) in symptom free patients and patients with persistent generalised lymphadenopathy was normal (greater than 83% of predicted values). Patients with the AIDS related complex, non-pulmonary Kaposi sarcoma, and non-pulmonary non-Kaposi sarcoma AIDS (that is, opportunist infections affecting other organs) had lower mean values for TLCO (77%, 70%, and 70% of predicted respectively). These values were significantly lower than values for symptom free patients. Lower mean values of 50% and 63% predicted TLCO were observed in patients during the acute and recovery phases of Pneumocystis carinii pneumonia. TLCO was also low in patients with lung mycobacterial infection and in a patient with lung Kaposi sarcoma. Forced expiratory volume in one second, peak expiratory flow, and maximal expiratory flow at 50% of vital capacity were significantly reduced only in patients with acute pneumocystis pneumonia. This study shows that abnormalities in the results of pulmonary function tests, particularly TLCO, although greatest in patients with pulmonary complications of AIDS, are also present in patients with AIDS but without other evidence of pulmonary disease, and in patients with the AIDS related complex. The predictive and prognostic implications of these findings require further investigation.

Influence of atopy on the clinical manifestations of coronavirus infection in adult volunteers

In an attempt to understand the relationship between viral upper respiratory tract infection and the underlying virological and immunological mechanisms, thirty-four volunteers were inoculated intranasally with coronavirus 229E; subsequent virus shedding and/or antibody rises, indicating active infection, were observed in twenty-nine. There was a greater increase in independently measured scores of clinical severity, e.g. cold symptoms, in those with detectable IgE in nasal secretions (P less than 0.01). A similar association was found between clinical scores and serum IgE concentrations greater than or equal to 150 IU/ml, but the relationship with systemic atopy, as assessed by skin-prick tests to common allergens, was less marked. A more detailed study of twelve of the infected volunteers failed to explain these findings on the basis of mast cell mediator release, as concentrations of leukotriene B4, the sulphidopeptide leukotriene C4, and histamine, were not appreciably elevated in the nasal secretions following virus inoculation. Similarly, there was no evidence that circulating coronavirus specific IgE was produced. Thus, this study suggest that atopy may be related to the severity of cold symptoms produced by coronavirus 229E, although the exact connection has yet to be determined.

Diagnostic specificity of a sandwich ELISA for Aspergillus-related diseases

A sandwich ELISA with specificity for a major antigen (Ag 7) of Aspergillus fumigatus has been compared with indirect ELISAs with use of crude antigenic (culture filtrate) extracts and found to have a sensitivity of 100% and specificity of 92.3% for antibody detection in sera of patients with allergic bronchopulmonary aspergillosis (ABPA) and aspergilloma. In the Ag 7 ELISA, all sera from groups with ABPA (21) and aspergilloma (15) had positive titers, and mean values for both these groups were significantly higher (p less than 0.001) than control levels. By comparison, in the indirect ELISAs, most sera of patients with ABPA were positive; the sensitivity was 81% to 90%, and the specificity was 87%. Sera from other disease groups including sera from 13 patients with farmer's lung, 16 with tuberculosis, and 10 individuals with positive prick test to either A. fumigatus or Alternaria alternata were also tested by both types of assay. Up to five of these sera elicited significant positive results in the indirect ELISA, and although two sera were also positive in the Ag 7-specific ELISA, these latter titers were both below the range of values for the sera from patients with ABPA. With the use of an IgG calibration curve, the sensitivity of the assay was determined as within the range of 1 to 10 microgram of specific IgG antibody per milliliter. The Ag 7-specific ELISA is therefore a highly specific, sensitive assay for antibody detection in Aspergillus-related diseases.

Enteral and systemic release of leukotrienes during anaphylaxis of Nippostrongylus brasiliensis-primed rats

Rats with acquired immunity to the intestinal nematode Nippostrongylus brasiliensis develop anaphylaxis after i.v. challenge with an extract of worm antigen, with the small intestine being the primary shock organ. In the present study we have shown that these events were associated with significant elevations in intestinal and plasma concentrations of leukotrienes LTB4 and LTC4. The changes were observed in immune rats over 10-, 30-, and 60-min intervals after antigen challenge but were absent in control animals. These lipid mediators were identified both in the perfusate of the gut lumen, which contained large quantities of mucus, and in homogenates of intestinal tissue. In addition, significant elevations in the concentrations of plasma LTB4 and LTC4 were detected in immune challenged rats but not in controls. Leukotrienes were identified by radioimmunoassay and validated by reverse-phase high-performance liquid chromatography (RP-HPLC). RP-HPLC analysis of SRS-A leukotrienes in immune challenged rats indicated that LTC4 was the predominant sulfidopeptide leukotriene at 10 min, with almost complete biodegradation to LTD4 and LTE4 within 30 min. Infected rats also had significant increases in the numbers of intestinal mucosal mast cells (MMC) and eosinophils. Evidence of MMC activation during anaphylaxis was obtained by showing significant elevations of intestinal and systemic concentrations of their exclusive serine enzyme, rat mast cell proteinase II (RMCPII). Thus, the release of substantial amounts of leukotrienes in the gut and plasma of N. brasiliensis-primed rats after interaction with worm antigens suggests that these potent mediators may play an important role in allergic-type hypersensitivity known to occur during immune reactions against parasitic helminths.

Enteral and systemic release of leukotrienes during anaphylaxis of Nippostrongylus brasiliensis-primed rats

Rats with acquired immunity to the intestinal nematode Nippostrongylus brasiliensis develop anaphylaxis after i.v. challenge with an extract of worm antigen, with the small intestine being the primary shock organ. In the present study we have shown that these events were associated with significant elevations in intestinal and plasma concentrations of leukotrienes LTB4 and LTC4. The changes were observed in immune rats over 10-, 30-, and 60-min intervals after antigen challenge but were absent in control animals. These lipid mediators were identified both in the perfusate of the gut lumen, which contained large quantities of mucus, and in homogenates of intestinal tissue. In addition, significant elevations in the concentrations of plasma LTB4 and LTC4 were detected in immune challenged rats but not in controls. Leukotrienes were identified by radioimmunoassay and validated by reverse-phase high-performance liquid chromatography (RP-HPLC). RP-HPLC analysis of SRS-A leukotrienes in immune challenged rats indicated that LTC4 was the predominant sulfidopeptide leukotriene at 10 min, with almost complete biodegradation to LTD4 and LTE4 within 30 min. Infected rats also had significant increases in the numbers of intestinal mucosal mast cells (MMC) and eosinophils. Evidence of MMC activation during anaphylaxis was obtained by showing significant elevations of intestinal and systemic concentrations of their exclusive serine enzyme, rat mast cell proteinase II (RMCPII). Thus, the release of substantial amounts of leukotrienes in the gut and plasma of N. brasiliensis-primed rats after interaction with worm antigens suggests that these potent mediators may play an important role in allergic-type hypersensitivity known to occur during immune reactions against parasitic helminths.

Enhancement of leukocyte cytotoxicity after exercise-induced asthma

We have previously shown that there were elevations of neutrophil chemotactic activity (NCA) and increases in the percentages of neutrophil and monocyte complement rosettes after exercise-induced asthma (EIA). These observations suggested that leukocyte activation may occur after EIA, possibly as a result of the release of mast-cell-associated mediators. In the present study, we have attempted to establish whether neutrophils and monocytes are functionally altered after EIA as assessed by changes in their cytotoxic capacity. Cytotoxicity was assessed by a direct visual killing assay using opsonized (complement-coated) schistosomula of Schistosoma mansoni as target organisms. Neutrophils and mononuclear cells obtained from 8 patients after exercise-induced asthma (EIA+ve) had increased cytotoxicity for opsonized schistosomula for as long as 60 min after exercise. These changes were preceded by elevations in the concentrations of serum high molecular weight NCA (which were maximal at 10 min after exercise). In asthmatic patients who did not develop exercise-induced asthma (EIA-ve), no significant increases in neutrophil or mononuclear cell killing of schistosomula, or serum NCA concentrations, were observed. There was a highly significant correlation (p less than 0.001) between the reduction in FEV1 and the increases in neutrophil cytotoxicity. In 5 EIA+ve patients, administration of disodium cromoglycate (cromolyn) prior to the exercise task inhibited both the enhancement in neutrophil and mononuclear cell cytotoxicity, as well as the elevations in circulating NCA and the reductions in FEV1.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging and the time course of semantic activation

Fifty-four young (M age = 20.2 years) and 54 elderly participants (M age = 68.4 years) completed a task in which a prime was followed by a target. People were to respond "yes" if the target was a word and "no" otherwise. On word-target trials, three kinds of prime were presented: associated (e.g., the prime-target pair DOG-CAT), unassociated (e.g., SEW-CAT), and neutral (e.g., BLANK-CAT). The stimulus onset asynchrony (SOA) between onset of the prime and target was varied, with SOAs of 150, 450, and 1,000 ms. The most important finding was an age difference in the minimum SOA at which priming (i.e., faster response time on associated than on unassociated trials) was observed. It is argued that the age difference in onset of priming reflects a slowing with age in one or more aspects of semantic activation. Contrary to the Hasher and Zacks (1979) hypothesis, there is evidence of an age difference in the speed of automatic activation.

Airways reversibility after prednisolone therapy in chronic asthma is associated with alterations in leukocyte function

In 6 patients with chronic asthma, we studied the effects of orally administered prednisolone on monocyte and neutrophil membrane receptor expression for IgG (Fc) and complement, neutrophil locomotion, and calcium ionophore-induced leukotriene C4 production by granulocytes. Prior to treatment, monocyte IgG (Fc) and complement receptor expression, but not neutrophil IgG (Fc) or complement receptor expression, were increased when patients were compared with nonasthmatic control subjects (p less than 0.01 and p less than 0.01, respectively). After a 7-day course of orally administered prednisolone (30 mg/day daily), the increases in peak expiratory flow rate were accompanied by significant decreases from baseline in the percent of monocyte IgG (Fc) (Day 3, p less than 0.001; Day 7, p less than 0.001), monocyte complement (Day 3, p less than 0.001; Day 7, p less than 0.001), and neutrophil complement rosettes (Day 3, p less than 0.02; Day 7, p less than 0.02), but not neutrophil IgG (Fc) rosettes. Neutrophil locomotion in vitro, in response to casein, from the asthmatics was enhanced when compared with cells from control subjects, and was significantly depressed following prednisolone. Each of the 6 subjects had a peripheral blood eosinopenia in response to prednisolone that corresponded to a decrease in the amount of immunoreactive LTC4 generated from granulocyte suspensions challenged with the calcium ionophore A23187. These findings suggest that prednisolone suppresses monocyte and neutrophil activation in chronic asthma and that this is accompanied by an improvement in lung function.

Nedocromil, a mucosal and connective tissue mast cell stabilizer, inhibits exercise-induced asthma

Nedocromil, the disodium salt of a pyranoquinoline dicarboxylic acid, has a similar profile of activity to disodium cromoglycate (DSCG) but appears to be more active in stabilizing mucosal-type mast cells. In a double-blind placebo-controlled trial nedocromil (2 mg) was given by inhalation to eight asthmatic patients prior to a treadmill exercise task. There was a significant reduction in the fall in FEV1 (P less than 0.01) and FVC (P less than 0.05) after nedocromil when compared to placebo. This study indicates that nedocromil might be an effective anti-asthma agent and in addition may help define the role of the mucosal mast cell.

Activated human eosinophils generate SRS-A leukotrienes following IgG-dependent stimulation

Eosinophils, a class of granular leukocytes, are prominent in many inflammatory processes, particularly in asthma, certain allergic diseases and during infections with helminthic parasites. Following incubation with the Ca ionophore A23187 (refs 1-4) (a non-physiological agent which circumvents membrane calcium-gating mechanisms), eosinophils generate large amounts of sulphidopeptide leukotrienes, potent inducers of smooth muscle constriction and mucus production. These are now known to represent the activity previously termed 'slow-reacting substance of anaphylaxis' (SRS-A) but attempts to identify a physiological stimulus for SRS-A production by eosinophils have so far been unsuccessful. The cells contain recognized receptors for IgG (Fc) and it is known that they adhere to, and can be activated by, contact with the surface of large organisms such as helminthic larvae. We show here that eosinophils, particularly when activated, produce sulphidopeptide leukotrienes after contact with large particles coated with IgG.

Mediators of hypersensitivity and "fog"-induced asthma

Seven asthmatic and five normal subjects inhaled increasing amounts of nebulized water ("fog"). Neutrophil chemotactic activity (NCA), histamine and FEV1 measurements were undertaken before and at time intervals after challenge. In asthmatics, the mean maximal reduction in FEV1 (+/- 1 SD) was 46.6% +/- 11.5; whereas, in normal subjects, the reductions were less than 20% of pre-challenge values after the inhalation of 33 ml of water. There were no significant differences in the pre-challenge values for NCA between the asthmatics and the normal controls. When the highest values for NCA during the 30 min after challenge in the asthmatics were compared with controls there was a significant increase (P less than 0.02). The percentage change in NCA was also significantly greater in the asthmatics compared with the controls at 10 min after challenge (P less than 0.05). Fog-induced NCA was shown to be associated with proteins with approximate molecular weight of 600,000 daltons (as assessed by gel filtration chromatography on Sephacryl-S400). There was an increase in plasma histamine in the asthmatics after challenge but this was not significantly greater than the controls. These findings support the view that mediators might be involved in fog-induced asthma, possibly as a result of mast cell degranulation by "osmotic shock".

Allergen-induced release of sulphidopeptide leukotrienes (SRS-A) and LTB4 in allergic rhinitis

Leukotrienes are a recently discovered group of arachidonic acid-derived lipid mediators. Using radioimmunoassay and high pressure liquid chromatography (HPLC), we have identified the SRS-A sulphidopeptide leukotrienes (LTC4, LTD4 and LTE4) in nasal washings from patients with allergic rhinitis who underwent nasal challenge with specific allergen. Smaller, but significant, amounts of LTB4 were also detected. The concentrations of nasal leukotrienes were directly related to the dose of allergen, and were recovered in washings in a time-dependent fashion after challenge. When the patients were subjected to methacholine nasal challenge on a control day, we found only negligible amounts of either the sulphidopeptide leukotrienes or LTB4. These findings support the view that LTC4, LTD4 and LTE4 might contribute to the pathogenesis of allergic rhinitis as a result of their recognized effects on mucous hypersecretion and vasopermeability, and that the potent chemoattractant LTB4 might be involved in the subsequent infiltration of inflammatory cells.

Inhibition of leukotriene C4 and B4 generation by human eosinophils and neutrophils with the lipoxygenase pathway inhibitors U60257 and BW755C

Human eosinophils and neutrophils have the capacity to generate leukotriene C4 (LTC4) and leukotriene B4 (LTB4) respectively when stimulated by calcium ionophore A23187. Leukotriene production by mixtures of these cell types was measured by radioimmunoassay for LTC4 and LTB4, and the specificities of the assays determined by assessing cross-reactivities with a number of other arachidonic acid metabolites. The IC50S for LTC4 and LTB4 in their respective assays were 1.76 +/- 0.04 nmol and 3.00 +/- 0.08 nmol. Cross-reactivity for anti-LTC4 was shown by leukotriene D4 (LTD4) (70%) and leukotriene E4 (LTE4) (8%), when compared to LTC4, whereas in the radioimmunoassay for LTB4, only the 5(S), 12(R) 6-trans isomer of LTB4 showed appreciable interaction (12%). LTC4 production by eosinophil enriched cell fractions obtained from metrizamide gradients was inhibited in a dose-dependent fashion by the prostacyclin analogue, 6,9-deepoxy-6,9-phenylimino-delta 6,8-prostaglandin I, (U60257) and by 3-amino-1-(3-trifluoromethyl phenyl)-2-pyrazole (BW755C). The ID50 values for U60257 and BW755C were 2 X 10(-6) and 5 X 10(-6) M respectively. This demonstration of LTC4 production by human eosinophils, which are known to be important cells in clinical asthma, provides an in vitro model to assess 5-lipoxygenase inhibitors in human tissue.