Viewpoints of adolescents with overweight and obesity attending lifestyle obesity treatment interventions: a qualitative systematic review

BACKGROUND

Current UK guidance recommends that adolescents with obesity attend a family-based multi-component obesity intervention. However, these programmes suffer from low recruitment and high rates of attrition. Understanding the views of adolescents is necessary for developing future interventions. The aim of this systematic review was to synthesize and explore the views of adolescents who have attended an obesity intervention.

METHODS

Published literature was identified by searching six databases. Studies of adolescents (12-17 years) who attended an obesity intervention were examined. Only studies that collected and analysed data qualitatively were included. Full texts were analysed using thematic synthesis.

RESULTS

Twenty-eight studies were included. Thirty-five analytical themes were developed that were broadly divided into seven domains. Key themes included ensuring adolescents receive a 'tailored intervention' that involves 'active engagement'. Support from professionals, family and peers were valued highly. Adolescents expressed 'prior fears of attending interventions' and wanted 'longer term support'. 'Enjoyment of sport and physical activity' was evident, and adolescents were strongly motivated by improving body image and social desirability.

DISCUSSION

Considering the views of adolescents attending obesity interventions may help to inform policy makers in the development of future interventions. This may lead to an improvement in recruitment and attrition rates.

Assessing the Impact of Tissue Target Concentration Data on Uncertainty in In Vivo Target Coverage Predictions

Understanding pharmacological target coverage is fundamental in drug discovery and development as it helps establish a sequence of research activities, from laboratory objectives to clinical doses. To this end, we evaluated the impact of tissue target concentration data on the level of confidence in tissue coverage predictions using a site of action (SoA) model for antibodies. By fitting the model to increasing amounts of synthetic tissue data and comparing the uncertainty in SoA coverage predictions, we confirmed that, in general, uncertainty decreases with longitudinal tissue data. Furthermore, a global sensitivity analysis showed that coverage is sensitive to experimentally identifiable parameters, such as baseline target concentration in plasma and target turnover half‐life and fixing them reduces uncertainty in coverage predictions. Overall, our computational analysis indicates that measurement of baseline tissue target concentration reduces the uncertainty in coverage predictions and identifies target‐related parameters that greatly impact the confidence in coverage predictions.

Impact of end-product inhibition on the determination ofin vitrometabolic clearance

End-product inhibition was explored as a mechanism for the lower clearance determination obtained from microsomes compared with hepatocytes. Triazolam, diazepam and phenytoin microsomal substrate depletion was reduced by 23, 34 and 39%, respectively, when incubated with their primary metabolites. Ki values of 28+/-6 and 11+/-1 microM were obtained when 4'-hydroxydiazepam and p-hydroxyphenytoin where incubated with diazepam and phenytoin, respectively. Alamethicin (a glucuronidation activator) was unsuccessful in alleviating these effects. IC50 values of 17, 32 and 18 microM for phenytoin and 83, 110 and 97 microM for diazepam were observed with salicylamide- (a glucuronidation inhibitor) treated hepatocytes, control hepatocytes and microsomes, respectively, when incubated with their primary metabolites. These differences suggest that metabolite concentrations in the vicinity of the enzyme are lower in hepatocytes compared with microsomes, reducing the likelihood of end-product inhibition in the former system. In conclusion, end-product inhibition may be more prominent in microsomes (in particular for substrate depletion assays where metabolism tends to be more extensive); results suggest that this phenomenon may contribute to the observed variations in metabolism characteristics and intrinsic clearance (CLint) between hepatocytes and microsomes.

In vivo 5-HT2A receptor blockade by quetiapine: an R91150 single photon emission tomography study

BACKGROUND

Atypical antipsychotic drugs are thought to show a high degree of 5-HT2A receptor blockade, which may prevent the emergence of extrapyramidal symptoms.

METHOD

5-HT2A binding was estimated using 123I-5-I-R91150 and single photon emission tomography (SPET) in six schizophrenic subjects treated with quetiapine at a mean (+/-SD) daily dose of 350+/-123 mg for at least 5 weeks and a matched sample of six healthy volunteers. Clinical and side-effect ratings were performed at baseline and at the time of SPET scanning. The reference region approach was used to define a 5-HT2A binding index in the frontal and temporal cortex.

RESULTS

Quetiapine treatment resulted in a significant decline in 5-HT2A receptor availability in the frontal cortex (mean 0.98+/-0.09) relative to healthy volunteers (mean 1.33+/-0.16). All patients showed improvements in clinical symptom or side-effect ratings. The mean frontal cortex:cerebellum ratio after quetiapine treatment was significantly negatively correlated with reduction in the Abnormal Involuntary Rating scale and Simpson-Angus scores (P<0.05 Bonferroni corrected), but not with the reduction in the scores from the scale for the assessment of positive symptoms, the scale for the assessment of negative symptoms, the Montgomery-Asberg depression rating scale or patient age.

CONCLUSION

Quetiapine treatment results in significant in vivo blockade of cortical 5-HT2A, similar to other atypical antipsychotic drugs. This effect may contribute to its placebo level extrapyramidal side-effect profile.

VACUTEX capillary action dressing: a multicentre, randomized trial

This article describes a preliminary study comparing the effect of VACUTEX capillary action wound dressing vs standard protocol for the treatment of sloughy and necrotic wounds. The study was carried out over a period of 5 months. Randomization was computer generated and batches of trial numbers and dressing allocation were delivered to each of the three study sites, sealed in opaque envelopes to ensure blinding of allocation. A total of 35 patient participants were recruited (17 VACUTEX 14, standard protocol, three withdrew, one died). All participants gave their consent to enter the study. All participants were assessed and photographs were taken on days 1, 8, 15, 22 and 29. Nursing assessments of size, site, depth, severity, tissue type of wound and causation were collected, as were demographic factors including mental status, primary/associated medical history, weight, height, and ethnic origin.

Design, expression and functional characterization of a synthetic gene encoding the Chlamydia trachomatis major outer membrane protein

A synthetic gene coding for the Chlamydia trachomatis serovar L2 major outer membrane protein (MOMP) was designed, constructed and expressed in Escherichia coli. The native amino acid sequence was reverse translated and the resulting nucleotide combinations manipulated in order to evenly distribute 25 unique restriction sites along the length of the gene while retaining the native amino acid sequence. The synthetic gene was cloned into a T7 promoter-controlled plasmid (pET-3a) and the expressed product was analyzed to assess antigenicity, cellular localization and function. Monoclonal antibodies specific for native MOMP reacted to the expressed product by immunoblot. Outer membrane fractionation confirmed that the processed protein was located in the outer membrane. MOMP expressed in E. coli and present in the outer membrane was shown to function as a general diffusion porin. This system provides the means to produce readily modifiable MOMP either in purified form or as a membrane-associated protein, and so facilitate the investigation of its functional, structural and antigenic properties.

Striatal and extra-striatal D(2)/D(3) dopamine receptor occupancy by quetiapine in vivo. [(123)I]-epidepride single photon emission tomography(SPET) study

BACKGROUND

Selective action at limbic cortical dopamine D(2)-like receptors could mediate atypical antipsychotic efficacy with few extrapyramidal side-effects.

AIMS

To test the hypothesis that quetiapine has 'limbic selective' D(2)/D(3) receptor occupancy in vivo.

METHOD

The high-affinity D(2)/D(3) ligand [(123)I]-epidepride and single photon emission tomography were used to estimate D(2)/D(3) specific binding and an index of relative percentage D(2)/D(3) occupancy in striatal and temporal cortical regions for quetiapine-treated patients (n=6). Quetiapine-, and previously studied typical-antipsychotic- and clozapine-treated patients were compared.

RESULTS

Mean (s.d.) relative percentage D(2)/D(3) receptor occupancy by quetiapine was 32.0% (14.6) in striatum and 60.1% (17.2) in temporal cortex (mean daily dose 450 mg: range 300-700 mg/day). Quetiapine treatment resulted in limbic selective D(2)/D(3) blockade similar to clozapine and significantly higher than typical antipsychotics.

CONCLUSIONS

Preliminary data suggest that limbic selective D(2)/D(3) receptor blockade is important for atypical drug action.

Experienced nurses learning with medical students: a case study

Although there are successful examples of interdisciplinary education this generally relates to pre-registration health-care professionals. Post-registration projects are usually confined to skills workshops or social science subjects, which rarely include medical staff. This project was unusual in its attempt to combine the needs of experienced practitioners with those of medical students. There are practical issues for this form of learning such as, the organization of modules into 'systems' when health-care professionals (as part of a parallel project) indicated their interests lay in courses that related to clinical practice organized around disease processes/conditions. This case study demonstrates that concerns related to the potential mismatch of clinical expertise, maturity and scientific background are not insurmountable problems, and that clear benefits can be gained. It could be argued that until pre- and post-graduate medical staff are integrated with other disciplines, the real benefits of shared understanding, enhanced team work and mutual respect will remain illusive. It is not anticipated that this form of learning would be suitable for the majority of practitioners, whose core needs are generally met by existing opportunities. However, there is a need for a greater depth of academic understanding particularly for those in senior positions or in specific specialized areas (also identified in the parallel study) and for those whose roles are expanding. These practitioners are more likely to have the ability to apply their new knowledge to clinical practice, using reflective techniques with minimal facilitation to enhance their established clinical expertise. For them this model of learning offers the opportunity to tailor education to the individual needs of the practitioner without the costly establishment of complete new programmes of learning. This case study proved particularly successful for the participants as they enhanced understanding and confidence in the knowledge underpinning their practice. This enabled them to better anticipate patients needs, to identify complications and initiate action at an earlier stage. Their appreciation of rationale underpinning medical treatment has enabled them to support junior medical staff, and to promote the continuity of appropriate care. They are more active in the education of patients, relatives and staff, and have identified specific developments which will be informed by the knowledge they have gained. It also proved beneficial to junior medical staff with whom interdisciplinary working has improved. Each organization involved in facilitating the initiative also benefited by gaining mutual understanding and appreciation of systems, constraints and opportunities. Equally, relationships among them have been strengthened and key issues with practical solutions have been identified to inform future joint ventures. Indications suggest that there would be value in using this case study to inform a structured pilot project involving other modules of learning and potentially other disciplines. If successful it could benefit all health-care professionals, particularly those senior staff who are expanding their roles and have educational needs unmet by existing provision. In addition to providing complementary opportunities this format provides a mechanism to enhance the mutual understanding essential to effective teamwork.

Introducing a lecturer-practitioner: the management perspective

The West Midlands Regional Health Authority Department of Nursing funded a 1-year study to look at 'Implementation aspects of the lecturer-practitioner role (in nursing)'. A feasibility study was carried out from November 1992 to October 1993 to address the issue and highlight areas requiring more in-depth study. Twenty-nine subjects working as or with lecturer-practitioners were interviewed using a semi-structured questionnaire. The interview was divided into two discrete parts. The first section contained a mixture of open and closed questions and the second section adopted a modified repertory grid technique. This paper provides the main results from the first half of the interview. The study describes in practical terms how managers need to plan for the introduction of a lecturer-practitioner post; the key responsibilities of the role; and a person specification. The work identifies clear prerequisite criteria for job role and gives guidance on lecturer-practitioner management and function.

Re-evaluation of hyaluronidase in peribulbar anaesthesia

AIMS/BACKGROUND

Hyaluronidase can augment the actions of local anaesthetics in peribulbar anaesthesia. However, evidence suggests satisfactory anaesthesia can be achieved using mixtures without hyaluronidase. A randomised double blind study was conducted on 50 patients, undergoing peribulbar anaesthesia, to validate this observation.

METHODS

Patients received a standard mixture of local anaesthetic (0.5% bupivacaine and 2% lignocaine in a 1:1 ratio) with or without hyaluronidase (25 IU/ml of mixture), pH values 5.16 and 5.24 respectively. Time taken to establish satisfactory anaesthesia to allow surgery was noted.

RESULTS

The onset time to globe akinesia in the control group ranged from 2 to 15 minutes (mean 5.64 and median 4 minutes) and in the hyaluronidase group from 2 to 12 minutes (mean 4.64 and median 4 minutes). The volume of local anaesthetic injected to achieve satisfactory anaesthesia ranged from 8 to 16 ml (mean 10.96, SD 1.95) in the control group and 10 to 18 ml (mean 11.64, SD 2.8) in the hyaluronidase group. A Mann-Whitney test to compare onset times to globe akinesia between groups gave a p value = 0.6 and 95% confidence interval (-1 to 2 minutes).

CONCLUSION

Addition of 25 IU/ml of hyaluronidase to a standard pH unadjusted local anaesthetic mixture does not significantly reduce the time to the onset of satisfactory globe akinesia.

Family reactions to restraints in an acute care setting

1. Families do not realize that a patient has a right to refuse restraints and that the family members have a voice in the decision-making process. 2. Families in general are interested in restraint issues but do not have information at their disposal. 3. Nursing staff should be encouraged to educate family members regarding restraints through open communication and printed material.

Accessory cells do not contribute to G-CSF or IL-6 production nor to rapid haematological recovery following peripheral blood stem cell transplantation

Haemopoietic recovery is more rapid after peripheral blood stem cell (PBSC) transplantation than after autologous bone marrow transplantation, and the aim of this study was to assess the role of the large number of lymphocytes and monocytes (accessory cells) in a PBSC leukapheresis product in this rapid regeneration. Haematological recovery was therefore assessed in 10 PBSC recipients with lymphoma or myeloma in whom monocytes and T cells were depleted by a median of 2.3 and 3.3 logs by CD34+ cell selection using the CEPRATE SC stem cell concentration system and compared with recovery in 59 recipients who received whole PBSC. After allowing for the number of progenitor cells reinfused, there was no significant delay in engraftment induced by accessory cell depletion. Plasma levels of granulocyte-colony stimulating factor (G-CSF), granulocyte/monocyte-colony stimulating factor (GM-CSF), interleukin-6 (IL-6), stem cell factor (SCF) and macrophage-inhibition factor-alpha (MIP-1-alpha) during the transplant procedure were similar whether or not accessory cells were given. The G-CSF and IL-6 levels rose between days 5 and 14 post transplantation to approximately 1 ng/ml and 50 pg/ml respectively. This study indicates that accessory cells reinfused with PBSC collections are not responsible for the subsequent cytokine profile or rapid haematological recovery.

Exploring music intervention with restrained patients

Roy's Adaptation Model is used in a case study approach to begin examining the potential of music intervention in hospitalized, restrained patients. Restraints were removed during the time in which the patient listened to a musical tape through a headset. Mr. D, presented in this case study, was one of the 30 medical-surgical patients who participated. His observable positive behaviors increased from 10 during the preintervention period to 12 during the musical intervention. Mr. D displayed no negative behaviors during the entire study period.

The effects of recombinant human granulocyte-macrophage colony stimulating factor on the neutrophil respiratory burst in the term and preterm infant when studied in whole blood

To investigate further the susceptibility to infection of newborn infants, particularly those born prematurely, we have used a "whole blood" flow cytometric assay to compare the respiratory burst activity in recombinant human granulocyte-macrophage colony stimulating factor "primed" neutrophils obtained from healthy adults, term infants, and preterm newborn infants. The use of whole blood avoids prior cell separation procedures that may cause artifactual activation or priming. In healthy adults (n = 21), the bacterial cell wall peptide N-formyl-methionyl-leucyl-phenylalanine induced little neutrophil respiratory burst activity, suggesting that the circulating cell is relatively quiescent. Prior exposure to recombinant human granulocyte-macrophage colony stimulating factor augmented the median N-formyl-methionyl-leucyl-phenylalanine response by 425%. In cord blood from full-term neonates (n = 9), recombinant human granulocyte-macrophage colony stimulating factor produced less enhancement of the N-formyl-methionyl-leucyl-phenylalanine response (345%), but the absolute level of respiratory burst activity was at least as great as in adults, suggesting that the neutrophils are fully functional and partially primed after delivery. In preterm infants receiving intensive care (n = 10), the degree of priming was similar to that in neutrophils from term infants (344%), although the absolute level of respiratory burst activity was reduced (p = 0.0003). In response to stimulation with phorbol ester, 73.5% (18-99%) (median and range) of neutrophils obtained from adults and 77.6% (50-92%) from term babies exhibit respiratory burst activity detectable in the whole blood assay. However, in neutrophils obtained from preterm infants, there was a significant reduction in the phorbol ester-induced respiratory burst, with only 32.9% (21-61%) of cells responding (p = 0.0129).

The formation of human synovial joint cavities: a possible role for hyaluronan and CD44 in altered interzone cohesion

During fetal development, cavitation occurs within the primitive skeleton along planes destined to become the articular surfaces of synovial joints. A histochemical study of human fetal limbs was undertaken to identify the cell types involved in this cavitation and the possible role of interactions between cells and extracellular matrix. Cryostat sections were stained with antibodies to CD68, factor VIII related antigen, prolyl hydroxylase, beta 1 integrin, VCAM-1, proliferating cell nuclear antigen, chondroitin-4 sulphate, chondroitin-6-sulphate, hyaluronan synthase and CD44. Similar sections were reacted for uridine diphosphoglucose dehydrogenase (UDPGD) and acid phosphatase activity. Hyaluronan was demonstrated using an aggrecan core protein hyaluronan binding region probe. Macrophages were present prior to cavitation in the periphery of joint interzones but not at the presumptive joint line in the central interzone. Fibroblastic cells were present throughout. Absence of local VCAM-1 expression indicated that cavitation was temporally distinct from full fibroblast-like synoviocyte differentiation. CD44 was expressed by interzone cells at all stages. Staining for hyaluronan and hyaluronan synthase, but not chondroitin sulphates was present in the interzone before and at the time of cavitation. UDPGD activity was increased in a narrow band of cells at the presumptive joint line prior to cavitation. These findings suggest that joint cavitation is dependent on the behaviour of fibroblastic cells and/or adjacent chondrocytes, rather than macrophages. Since UDPGD activity is involved in hyaluronan synthesis, it is proposed that joint cavitation is facilitated by a rise in local hyaluronan concentration in an area of tissue where cohesion is dependent on the interaction between cellular CD44 and extracellular hyaluronan. As proposed by Toole et al. (1984) such a local rise in hyaluronan concentration may lead to a switch from intercellular cohesion to dissociation, leading to tissue cavitation.

Development of a simplified single-apheresis approach for peripheral-blood progenitor-cell transplantation in previously treated patients with lymphoma

PURPOSE

The aims of this study were to develop a simplified, safe, and cost-effective peripheral-blood progenitor-cell (PBPC) mobilization protocol.

PATIENTS AND METHODS

Twenty-six patients with relapsed or resistant lymphomas were entered onto a sequential cohort study in which schedules of various granulocyte colony-stimulating factor (G-CSF) were administered after cyclophosphamide 1.5 g/m2. Hematologic recovery after high-dose carmustine (BCNU) etoposide, cytarabine, and melphalan (BEAM) chemotherapy was compared with that of 46 patients who received autologous bone marrow transplantation (ABMT) without growth factors and 28 patients who received ABMT followed by G-CSF.

RESULTS

When G-CSF (10 micrograms/kg/d) was administered from the day after the cyclophosphamide, neutropenia developed on day 8 followed by an abrupt increase in the WBC count. The optimal time for PBPC harvesting was the day on which the postnadir WBC count was greater than 8.0 x 10(9)/L, as shown by CD34+ cell counts and granulocytic-macrophage colony-forming cell (GM-CFC) assays. The reproducibility of the response was such that routine monitoring of CD34+ cell counts and GM-CFC was not necessary. A single leukapheresis on this day was adequate for prompt hematologic engraftment, and posttransplant G-CSF made little further impact on the rapid recovery. Compared with both control groups, the use of PBPC led to more rapid neutrophil recovery, markedly accelerated platelet recovery, less use of antimicrobial agents and parenteral nutrition, and more than 10 days earlier discharge from hospital. All of these differences were highly significant (P < .01).

CONCLUSION

A simplified mobilization protocol is described that requires only one apheresis to achieve rapid hematologic engraftment.

The effects of gestation on circulating progenitor cells

The frequency of BFU-E in second-trimester fetal blood (484 +/- 104/10(5)) falls progressively during gestation to a value of 69 +/- 41/10(5) in cord bloods of 36 weeks gestation and beyond, but this is still significantly greater than adult blood values of 14 +/- 8 (P < 0.01). BFU-E obtained from unfractionated peripheral blood mononuclear cells from fetuses/neonates less than 36 weeks gestation were more sensitive to erythropoietin than adult BFU-E, but the sensitivity of highly purified BFU-E obtained from second-trimester fetal liver was similar to that in adult cells. Almost maximal growth of BFU-E from purified fetal progenitor cells could be achieved with erythropoietin alone, whereas adult cells required the presence of other factors with 'burst-promoting activity'.

Expression and dynamic modulation of the human granulocyte colony-stimulating factor receptor in immature and differentiated myeloid cells

In this study we have examined the expression and modulation of the human granulocyte colony-stimulating factor (G-CSF) receptor (R) in immature and differentiated myeloid cells using a 125I labelled human G-CSF analogue (TG50). Equilibrium binding data revealed a single affinity class of receptor on all cell types expressing G-CSFR (KD 235-606 pM) with neutrophils expressing 2883 +/- 672 Rs/cell. Rapid internalization of surface receptor-bound ligand at 37 degrees C was detected in both immature cells (U937) and neutrophils with > 70% of specifically bound ligand internalized within 5 min. Concentration-response data showed that the level of occupancy of neutrophil G-CSFRs by ligand at 37 degrees C was approximately 5-fold greater than predicted by equilibrium binding data and correlated closely with concentration-response data for biological activity. Re-expression of G-CSFRs following down-regulation by internalization was not detected. Down-regulation of the neutrophil G-CSFR by several agents including granulocyte-macrophage colony-stimulating factor (GM-CSF), tumour necrosis factor (TNF), lipopolysaccharide (LPS), f-met-leu-phe (fMLP), phorbol ester (TPA) and C5a was observed at 37 degrees C but not at 4 degrees C. In contrast, G-CSFRs on immature myeloid cells were significantly down-regulated by TPA only. Differentiation of myeloid leukaemic cell line HL-60 with DMSO, a frequently used model of granulocytic differentiation, was associated with a significant reduction in G-CSFR expression (11 +/- 5% of control) whereas treatment with retinoic acid led to increased G-CSFR expression (161 +/- 3%).

Dynamic modulation of the cell surface expression of the granulocyte-macrophage colony-stimulating factor receptor

The GM-CSF receptor (GM-CSFR) is composed of alpha and beta subunits. Surface expression of the alpha chain alone leads to low affinity GM-CSF binding and of both subunits to high affinity binding; the beta chain is required for transducing a proliferative signal. Studies of GM-CSFR expression have concentrated largely on static events occurring under conditions of binding equilibrium. We have examined the dynamic regulation of high and low affinity GM-CSFR expression in neutrophils (1100 +/- 200 R/cell, KD 50 +/- 15 pM) and a GM-CSF dependent human leukaemic cell line, TF-1 (2000 +/- 450 R/cell KD 15 +/- 5 pM) and 8600 +/- 1150 R/cell KD 1.8 +/- 0.3 nM). The addition of GM-CSF to TF-1 cells (350 pM, 4 h at 37 degrees C) caused a reduction in subsequent binding of 125I-GM-CSF at low ligand concentration (100 pM) (following a low pH wash to remove surface bound ligand) to 16 +/- 4% and a reduction in binding at high ligand concentration (2 nM 125I-GM-CSF) to 36 +/- 9% of control. Scatchard analysis showed complete down-regulation of high affinity GM-CSFR and a significant reduction in low affinity GM-CSFR. In neutrophils, concentration-response curves of ligand induced receptor down-regulation at 37 degrees C showed that observed down-modulation was more than 10-fold greater than predicted by static equilibrium binding data and correlated closely with GM-CSF priming of the neutrophil respiratory burst. The addition of IL-3 to TF-1 cells at 37 degrees C reduced 100 pM 125I-GM-CSF binding to 18 +/- 4% and 2 nM 125I-GM-CSF binding to 46 +/- 5% of control. TF-1 cells, but not neutrophils, were able to re-express GM-CSFR following removal of GM-CSF from medium. TF-1 proliferation assays showed that pulsed GM-CSF (0.35-3.5 nM) for up to 4 h did not cause a significant increase in 3H-thymidine incorporation which required the continued presence of GM-CSF (control 2875 +/- 208 cpm, pulsed GM-CSF 5 ng/ml 4972 +/- 1344, continuous GM-CSF 5 ng/ml 17249 +/- 2982). Therefore, proliferation of TF-1 cells required the continued presence of GM-CSF at a time when there was no detectable surface high affinity GM-CSFR.(ABSTRACT TRUNCATED AT 400 WORDS)

In vivo and in vitro effects of 3-hydroxypyridin-4-one chelators on murine hemopoiesis

The effects of 3-hydroxypyridin-4-one (HPO) iron chelators and desferrioxamine (DFO) on murine hemopoiesis in vivo and in vitro have been compared in order to investigate the mechanism by which leucopenia in mice and granulocytopenia in man occurs with 1,2-,dimethyl-HPO (CP20). Administration of 60 doses of 200 mg/kg CP20 to Balb/c mice resulted in significant anemia, lymphopenia and granulocytopenia accompanied by bone marrow hypocellularity. DFO and CP94 (1,2,diethyl-HPO) at the same dose also caused lymphopenia but marrow cellularity was unaffected. When marrow from untreated mice was incubated with HPOs and DFO, erythroid burst-forming cells (BFU-E) and granulocyte/macrophage colony forming units (CFU-G+Mac), colony growth was inhibited in a dose-dependent manner at micromolar concentrations. The addition of iron to saturate the chelators abrogated the effects of DFO, but not those of the HPOs. With the HPO-iron complexes, addition of sufficient iron to saturate the transferrin in the medium reversed the inhibitory effects of the relatively hydrophilic CP20-iron complex but not those of the more lipophilic CP94-iron complex. Addition of further iron-saturated transferrin also corrected inhibition by the CP94-iron complex. These results show that HPO-iron complexes potentially have antiproliferative effects unlike DFO-iron complex (FO). The difference in the relative effects of CP20 to CP94 on hemopoiesis in vivo and in vitro suggests that additional factors to those inhibiting hemopoiesis in marrow cultures may operate with the long-term administration of iron chelators in vivo.

Painful transthoracic needle biopsy: a sign of neurogenic tumor

Neurogenic tumors most commonly appear initially as posterior mediastinal masses. These tumors, however, may occur in other intrathoracic locations and present a diagnostic challenge. In such cases transthoracic fine-needle aspiration (FNA) often is used to make a definitive diagnosis. This procedure usually does not result in severe pain. We report two patients who experienced severe pain during transthoracic FNA of neurogenic tumors. We believe that severe pain associated with transthoracic needle biopsy of an intrathoracic mass is suggestive of a neurogenic tumor. When pain accompanies this procedure, a cytopathologist should be notified so that specific immunostaining techniques can be performed to confirm the diagnosis.

Evaluation of the humoral immune response in trachoma to Chlamydia trachomatis major outer membrane proteins by sequence-defined immunoassay

The Chlamydia trachomatis immunodominant major outer membrane protein (MOMP) is both a target of neutralizing antibodies and the serotyping antigen and thus has been a focus of diagnostic, seroepidemiologic, and experimental investigations. The microimmunofluorescence (MIF) test has been the principal tool in serologic investigations of chlamydial infections but is difficult and expensive for routine use; moreover, since it uses whole organisms as antigen, it is incapable of revealing the molecular specificity of the humoral response to infection. These limitations were resolved by using synthetic peptides corresponding to serovar-specific antigenic regions of MOMP in an ELISA-based format to analyze the serospecificity of sera from trachoma cases. The ELISA reaction to the surface-exposed MOMP sequence variable segment 1 was immunodominant and serovar-specific and was in concordance with serovar specificity according to paired MIF test determinations. Understanding the patterns of humoral responses to MOMP determinants in patient populations will advance our knowledge of their role in the immunobiology of naturally acquired infection.

Down-regulation of human protein kinase C alpha is associated with terminal neutrophil differentiation

We have established an RNase protection method to quantify the expression of mRNA for the human protein kinase C (PK-C) isoforms alpha, beta 1, beta 2, and gamma. This was used to investigate whether each isoform is differentially expressed during the differentiation of hematopoietic cells. Myeloid and lymphoid cells express PK-C alpha, beta 1, and beta 2 mRNAs in various proportions. PK-C gamma mRNA was detected in human brain, but not in hematopoietic cells. PK-C alpha mRNA decreases as HL-60 cells mature to a neutrophil phenotype in response to retinoic acid, but its abundance does not change during monocytic differentiation in response to vitamin D3. PK-C alpha mRNA and protein were undetectable in peripheral blood neutrophils, but are present in monocytes. The mRNAs for PK-C beta 1 and beta 2 isoforms increase during HL-60 differentiation and are expressed in both neutrophils and monocytes. Therefore, the PK-C alpha isoform is specifically down-regulated during human neutrophil terminal differentiation. These data suggest that mature neutrophil functions do not require the PK-C alpha isoform.

The effect of macrophage colony-stimulating factor on haemopoietic recovery after autologous bone marrow transplantation

Macrophage colony-stimulating factor (M-CSF) is active in the late stages of monocyte maturation, activates mature monocyte-macrophages and enhances their production of various other cytokines. We have examined the effects of a 21 d course of escalating doses of M-CSF purified from human urine (hM-CSF) on recovery following autologous bone marrow transplantation (ABMT) in 20 patients with malignant lymphomas. Four patients were treated at each dose level of 4, 8, 16, 32 and 64 x 10(6) U/m2/d and results compared to 46 concurrent controls. There was no significant difference in recovery to an absolute neutrophil count (ANC) of 0.5 x 10(9)/l (median 20 d in hM-CSF group versus 22 in controls) or in recovery of platelets to 50 x 10(9)/l (32 d versus 39 d, 0.05 less than P less than 0.1); hM-CSF patients received a median of 81 platelet units following ABMT (controls 112 units, P = NS). hM-CSF patients had a median of 5.5 d with fever greater than 37.5 degrees C (control 8, P = NS), received parenteral antibiotics for 14.5 d (control 17, P = NS) and had a 50% incidence of bacteraemia (control 48%). hM-CSF treated patients were discharged by a median of day 29 following transplantation (control 33, P less than 0.05). Platelet and neutrophil recovery correlated significantly with the number of marrow mononuclear cells (MNC) reinfused in the hM-CSF group (P = 0.05 and P = 0.014 respectively) but not in controls. Subgroup analysis showed that hM-CSF patients receiving greater than 2 x 10(8) MNC/kg body weight reached an ANC of 0.5 x 10(9)/l by a median of day 16.5 (control 18.5, NS), became platelet transfusion independent by day 17 (control 29, P less than 0.05) and reached a platelet count of 50 x 10(9)/l by day 21 (control 40, P less than 0.05). No significant toxicity attributable to hM-CSF treatment was seen. These results suggest that hM-CSF accelerates platelet recovery following ABMT and that relatively large marrow innocula are required to see this effect.

Fc gamma RII, but not erythropoietin or GM-CSF, mediates calcium mobilization in fetal hemopoietic blast cells

A proportion of fetal liver hemopoietic blast cells express Fc gamma RII, and addition of the anti-Fc gamma RII monoclonal antibody CIKM5 induces a rise in calcium in these cells in suspension. Although these cells are thus capable of mobilizing intracellular calcium in response to surface receptor mediated events, neither granulocyte-macrophage colony-stimulating factor (GM-CSF) nor erythropoietin produced detectable changes in intracellular calcium ion concentration in these cells.

Comparison of plain and alkalinized local anaesthetic mixtures of lignocaine and bupivacaine for elective extradural caesarean section

We have examined a local anaesthetic mixture of 0.5% bupivacaine 10 ml and 2% lignocaine 10 ml with adrenaline 1 in 200,000, to which 8.4% sodium bicarbonate 2 ml was added, for extradural Caesarean section. The alkalinized mixture of local anaesthetics produced a block of more rapid onset and density than a mixture of bupivacaine and lignocaine alone (P less than 0.001).

The molecular origin of birefringence in skeletal muscle. Contribution of myosin subfragment S-1

The state of optical polarization of He-Ne laser light diffracted by single skinned frog skeletal muscle fibers has been determined after decoration of the thin filaments of rigor fibers with exogenous S-1. Light on the first diffraction order was analyzed using optical ellipsometry for changes occurring in total birefringence (delta nT) and total differential field ratio (rT) and the experimental results compared with theoretical predictions. Fibers were examined with SDS-gel electrophoresis and electron microscopy as independent assays of S-1 binding. The binding of S-1 to the thin filaments caused a significant increase in rT and a small but significant decrease in delta nT. Release of bound exogenous S-1 with magnesium pyrophosphate demonstrated that the effect of S-1 on the optical parameters was reversible and both electrophoresis and electron microscopy demonstrated the presence of S-1 specifically bound to the thin filaments. Model simulations based on the theory of Yeh, Y., and R. Baskin (1988. Biophys. J. 54:205-218) showed that the values of delta nT and rT were sensitive to the axial bonding angle of exogenous S-1 as well as to the volume fraction of added S-1. Analysis of the data in light of the model showed that an average axial S-1 binding angle of 68 degrees +/- 7 degrees best fit the data.

Lack of effect of granulocyte-macrophage and granulocyte colony-stimulating factors on cultured human endothelial cells

The hematopoietic growth factors, granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF), enhance the effector functions of mature myeloid cells, including the interaction with vascular endothelium. We examined the direct effect of recombinant human GM-CSF (rhGM-CSF) and recombinant human G-CSF (rhG-CSF) on the growth and function of cultured human umbilical vein endothelial cells (HUVEC). Endothelial cell growth supplement (ECGS) increased the proliferation of passaged and primary cells by 305% +/- 45% (mean +/- SEM, n = 5, P less than .01) over control cells at 4 days; GM-CSF and G-CSF had no effect. Endothelial cell procoagulant activity was increased after 4-hour incubation with recombinant interleukin-1 beta (IL-1 beta) 10 U/mL and recombinant tumor necrosis factor (TNF) 10 U/mL to 1,721% +/- 376% (n = 7, P less than .005) and 247% +/- 71% (n = 4) of control levels, respectively. gamma-Interferon (gamma-IFN) 50 U/mL had no direct effect of its own but was able to prime the response to IL-1 beta. There was no direct or priming effect of GM-CSF (1 ng to 1 microgram/mL) on the expression of procoagulant activity in endothelial cells. GM-CSF and G-CSF (1 ng/mL to 1 microgram/mL) had no effect on the expression of either tissue plasminogen activator (tPA) or plasminogen activator inhibitor-1 (PAI-1) by endothelial cells. The secretion of tPA by endothelial cells was increased, however, after 24-hour incubation with thrombin 4 U/mL (314% +/- 72% of control levels, n = 5, P less than .025). The production of PAI-1 was increased by TNF 200 U/mL (241% +/- 44% of control, n = 3, P less than .005), thrombin 4 U/mL (180% +/- 12% of control, n = 5, P less than .0005) and IL-1 beta 10 U/mL (275% +/- 44% of controls, n = 5, P less than .0005). In four experiments, endothelial cells showed no specific binding of 125I-GM-CSF, whereas peripheral blood (PB) neutrophils demonstrated the presence of 802 +/- 78 high-affinity receptors for GM-CSF. Thus, we found no effect of rhGM-CSF or rhG-CSF on the proliferation activities by these cells. These findings are in accordance with the lack of demonstrable receptors for GM-CSF on cultured HUVEC.

Sphingosine inhibits angiotensin-stimulated aldosterone synthesis

Sphingosine and other protein kinase C inhibitors were tested for their ability to inhibit aldosterone synthesis by bovine adrenal glomerulosa cells. Sphingosine inhibited angiotensin (AII)-stimulated aldosterone synthesis (IC50 of 5 microM). At doses that totally blocked steroidogenesis, sphingosine did not affect protein synthesis or [125I]AII binding to cells. Sphingosine also inhibited dibutyryl cyclic AMP (dbcAMP)-stimulated aldosterone synthesis. Sphingosine inhibited pregnenolone synthesis from cholesterol, but not the conversion of progesterone or 20 alpha-hydroxycholesterol to aldosterone. These results suggest that sphingosine inhibits steroidogenesis at a locus close to that where stimulation occurs by AII and dbcAMP. Other protein kinase C inhibitors were tested. Retinal, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7), and staurosporine inhibited aldosterone synthesis stimulated by AII and dbcAMP. Retinal and H-7 also inhibited progesterone conversion to aldosterone, and retinal blocked [125I]AII binding. Staurosporine was more specific, inhibiting AII-stimulated aldosteronogenesis at concentrations which had little effect on conversion of progesterone to aldosterone. Because they inhibited dbcAMP stimulation, none of the inhibitors was sufficiently specific to use as a probe of the role of protein kinase C. The IC50 of sphingosine suggests that this or related products of lipid hydrolysis could act as endogenous regulators of adrenal cell function.

Oral premedication in children. A comparison of trimeprazine with a trimeprazine, droperidol and methadone mixture

One hundred children who presented for minor general surgical procedures were randomly assigned to receive one of two oral premedications. Those in group A (n = 50) were given 3 mg/kg of trimeprazine and those in group B (n = 50) a mixture of trimeprazine 1.0 mg/kg, droperidol 0.15 mg/kg and methadone 0.08 mg/kg. Patients in group B were more likely to be asleep on arrival in the anaesthetic room (p less than 0.02) and were less likely to be distressed at induction of anaesthesia (p less than 0.02). Thiopentone requirements were less in group B (p less than 0.001). The incidence of side effects was similar in the two groups. It is concluded that the mixture produces more satisfactory sedation than trimeprazine.

Isoquinolinesulfonamide protein kinase inhibitors H7 and H8 enhance the effects of granulocyte-macrophage colony-stimulating factor (GM-CSE) on neutrophil function and inhibit GM-CSF receptor internalization

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) increases neutrophil surface expression of the cellular adhesion molecule CD11b and primes the respiratory burst stimulated by the bacterial peptide f-met-leuphe (FMLP). We have examined the effects of the isoquinolinesulfonamide protein kinase inhibitors H7 and H8 on these functions of GM-CSF using whole blood assays. Concentrations of H7 and H8 that inhibited the 12-O-tetradecanoyl-phorbol-13-acetate (TPA) stimulated upregulation of CD11b expression and activation of the respiratory burst, both augmented the effects of GM-CSF. H7 and H8 enhanced the GM-CSF-stimulated increase in CD11b expression to 215% +/- 10% (P less than .05) and 233% +/- 45% (P less than .05), respectively, of the value obtained with GM-CSF alone. The GM-CSF priming of the FMLP-stimulated oxidative burst was increased to 190% +/- 44% (P less than .01) by preincubation with H7 and to 172% +/- 25% (P less than .01) with H8. Preincubation with H8 did not affect overall binding of 125I-GM-CSF to neutrophils, but inhibited GM-CSF receptor internalization after ligand binding (P less than .05). These data indicate that the effects of GM-CSF are not mediated by protein kinase C and that a phosphorylation event down-modulates the neutrophil response to GM-CSF. It suggests that internalization of the receptor-ligand complex is not a rate-limiting step in signal transduction, and that regulation of the rate of internalization may be an important level of control of the activity of GM-CSF.