Leptospirosis: a case report of a patient with pulmonary haemorrhage successfully managed with extra corporeal membrane oxygenation

Leptospirosis is a zoonosis of worldwide significance. Pulmonary involvement is common but often mild and of little clinical significance. However, over the last two decades an increasing number of cases have been reported with pulmonary haemorrhage as a prominent feature [Carvalho CR, Bethlem EP. Pulmonary complications of leptospirosis. Clin Chest Med, 2002;23(2):469-78]. These cases are particularly challenging to treat as they often have resistant hypoxaemia despite maximal invasive mechanical ventilation. Consequently, there is a high mortality rate. Here, we present a case of severe leptospirosis complicated by massive pulmonary haemorrhage which was successfully managed by extra corporeal membrane oxygenation (ECMO).

A distinct subset of chemokines dominates the mucosal chemokine response in inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is characterised by intense mucosal recruitment of activated leukocytes. Chemokines determine inflammatory leukocyte recruitment and retention.

AIM

To compare expression of the entire chemokine family within colonic mucosa from IBD patients and uninflamed controls.

METHODS

A microarray of cDNAs, representing every member of this superfamily and their cognate receptors, was hybridised with probes derived from colonoscopic biopsies.

RESULTS

A distinct subset of chemokines, consisting of CXCLs 1-3 and 8 and CCL20, was upregulated in active colonic IBD, compared with uninflamed areas or tissue from controls. Increased expression of their cognate receptors, CXCR1, CXCR2 and CCR6, was confirmed by quantitative PCR and immunohistochemistry. An identical chemokine response was induced in Caco-2 cells by stimulation with interleukin (IL)-1beta, but not tumour necrosis factor-alpha (TNF-alpha). By contrast, IL-1beta and TNF-alpha were synergistic in an HT29 cell line and primary keratinocytes.

CONCLUSIONS

IL-1beta and TNF-alpha appear to be the pivotal mediators of a previously unidentified coordinated epithelial chemokine response that dominates the mucosal chemokine environment in inflamed IBD tissue.

Investigation of systems to prevent diversion of opiate drugs in general practice in the UK

BACKGROUND

Statutory regulations govern the procedures that must be followed by general practitioners (GPs) in the UK to minimise the risk of diversion of prescribed opiate drugs for illicit use. However, evidence presented at the trial of Harold Shipman, a GP convicted of murdering patients with diamorphine, suggests that the regulations and monitoring of GPs' prescribing are failing.

AIM

To assess the policies followed by general practices in Leicestershire and Rutland with regard to the controlled drugs regulations.

METHODS

A semi-structured interview was administered to a purposeful sample of lead GPs to explore how their practices applied the regulations. The controlled drugs registers and drug storage facilities in these practices were inspected. A questionnaire was sent to all the remaining practices to seek information about their application of the regulations, any concerns they had about the regulations, and any suggestions for improving them.

RESULTS

Of the 142 general practices in Leicestershire, the lead GP in 14 took part in the interviews. Respondents expressed dissatisfaction with current policies including the design of controlled drug registers, and generally supported the reintroduction of an inspection scheme. Ninety (70.9%) of the 127 practices to whom the questionnaire was sent responded and, of these, 31 (34.4%) no longer held a supply of controlled drugs. Those that did hold controlled drugs indicated concern about the regulations, confusion about some aspects including the return and disposal of unused drugs, and a desire for advice and support in the implementation of the regulations. Forty two of the 59 respondents who held a supply of controlled drugs (71.2%) would welcome regular inspection.

CONCLUSION

GPs are confused about the controlled drugs regulations and have little support in implementing them. The suspension of inspection schemes has reduced the amount of advice and support available to them and, in consequence, the regulations are interpreted differently in different practices. These findings are cause for concern about the risk of diversion of controlled drugs, and illustrate how patient safety systems can decay when they are not maintained.

Cellular immune responses to influenza

Cellular immune responses are believed to play an important role in controlling influenza infection. CD4+ and CD8+ T cell responses are well described and CD8+ immunity is of paramount importance in killing virally infected cells. In the past few years several novel techniques have been devised which allow quantification of antigen-specific cellular immune responses and these will be reviewed briefly. Influenza-specific cellular immunity is elicited following natural infection and several viral proteins have been identified as targets for cellular responses. Cellular immunity is detectable throughout life in most donors but there is clear evidence of impaired cellular immunity in the elderly, a population at particular risk of influenza infection. This finding must be viewed against the background of 'immune senescence' that is documented with aging. Cellular responses are able to provide heterosubtypic immunity to influenza viral antigens. As such the induction of cellular immune responses is a highly desirable aim of vaccination protocols. Induction of cellular immunity with conventional formalin-inactivated vaccine is poor although some improvement may be derived from novel forms of vaccine delivery such as the use of adjuvanted carriers. Nevertheless, a range of new vaccines is being developed which are more effective in priming cellular responses. Although there is relatively little detail on the nature of the cellular response induced by these agents, they hold out the promise of more effective and durable protection from influenza infection.

HLA class I-minor histocompatibility antigen tetramers select cytotoxic T cells with high avidity to the natural ligand

INTRODUCTION

Cytotoxic T cells specific for the hematopoietic system-restricted minor histocompatibility antigens HA-1 and HA-2 are potential tools for the treatment of relapsed leukemia after minor histocompatibility antigen mismatched bone marrow transplantation. HA-1/HA-2-specific cytotoxic T cells with strong cytotoxic activity against HA-1/HA-2 positive target cells can be generated in vitro using HA-1 and HA-2 peptide-pulsed dendritic cells as antigen presenting cells.

MATERIAL AND METHODS

We used HLA-A2 HA-1/HA-2 tetramers (HA-1(A2)/HA-2(A2) tetramers) to monitor the in vitro generation of HA-1- or HA-2-specific cytotoxic T cells.

RESULTS

We show that the intensity of the tetramer-staining of the HA-1/HA-2-specific cytotoxic T cells strongly correlates with their capability to recognize mHag positive target cells. The bright tetramer-staining cytotoxic T cells lyse target cells expressing the natural ligand. The dim tetramer-staining cytotoxic T cells fail to lyse natural ligand positive target cells and lyse peptide-pulsed target cells only. The frequency of bright tetramer-staining, high avidity minor histocompatibility antigen-specific CTLs increases significantly upon appropriate antigen-specific restimulations.

CONCLUSION

Our results demonstrate that HLA class I-minor histocompatibility antigen tetramers are useful tools for monitoring and selection of high avidity HA-1- and HA-2-specific cytotoxic T cells for adoptive immunotherapy.

Developments in the treatment of post-transplant viral disease

Stem cell transplantation is a potentially curative procedure for many types of haemopoietic malignancy but is associated with a period of intense immunosuppression which may last for 1 to 2 years. During this time new viral infections or reactivation of endogenous, latent virus can lead to a variety of clinical symptoms which, together, make a significant contribution to the morbidity and mortality of the procedure. Improvements in viral detection, prophylaxis and treatment of established disease are helping to minimize the clinical impact of viral disease, but a definitive solution to this problem must await improvements in our ability to reconstitute an effective immune system. Each of the viruses implicated in post-transplant disease has a unique relationship with the host immune system, and there is every hope that improvements in our understanding of viral immunology will be translated into more effective clinical control.

Influenza virus lung infection protects from respiratory syncytial virus-induced immunopathology

The effect of infection history is ignored in most animal models of infectious disease. The attachment protein of respiratory syncytial virus (RSV) induces T helper cell type 2-driven pulmonary eosinophilia in mice similar to that seen in the failed infant vaccinations in the 1960s. We show that previous influenza virus infection of mice: (a) protects against weight loss, illness, and lung eosinophilia; (b) attenuates recruitment of inflammatory cells; and (c) reduces cytokine secretion caused by RSV attachment protein without affecting RSV clearance. This protective effect can be transferred via influenza-immune splenocytes to naive mice and is long lived. Previous immunity to lung infection clearly plays an important and underestimated role in subsequent vaccination and infection. The data have important implications for the timing of vaccinations in certain patient groups, and may contribute to variability in disease susceptibility observed in humans.

Sequencing and expression analysis of the serine protease gene cluster located in chromosome 19q13 region

The human kallikrein gene cluster, located in the chromosome band 19q13, contains several tissue-specific serine protease genes including the prostate-specific KLK2, KLK3 and prostase genes. To further characterize the gene cluster, we have mapped, sequenced, and analyzed the genomic sequence from the region. The results of EST database searches and GENSCAN gene prediction analysis reveal 13 serine protease genes and several pseudogenes in the region. Expression analysis by RT-PCR indicates that most of these protease genes are expressed only in a subset of the 35 different normal tissues that have been examined. Several protease genes expressed in skin show higher expression levels in psoriatic lesion samples than in non-lesional skin samples from the same patient. This suggests that the imbalance of a complex protease cascade in skin may contribute to the pathology of disease. The proteases, excluding the kallikrein genes, share approximately 40% of their sequences suggesting that the serine protease gene cluster on chromosome 19q13 arose from ancient gene duplications.

Tetrameric HLA class I-minor histocompatibility antigen peptide complexes demonstrate minor histocompatibility antigen-specific cytotoxic T lymphocytes in patients with graft-versus-host disease

Graft-versus-host disease (GvHD) is a chief complication of allogeneic bone marrow transplantation. In HLA-identical bone marrow transplantation, GvHD may be induced by disparities in minor histocompatibility antigens (mHags) between the donor and the recipient, with the antigen being present in the recipient and not in the donor. Cytotoxic T lymphocytes (CTLs) specific for mHags of the recipients can be isolated from the blood of recipients with severe GvHD (ref. 3). A retrospective study demonstrated an association between mismatch for mHags HA-1, -2, -4 and -5 and the occurrence of GvHD in adult recipients of bone marrow from HLA genotypically identical donors. Tetrameric HLA-peptide complexes have been used to visualize and quantitate antigen-specific CTLs in HIV-infected individuals and during Epstein-Barr virus and lymphocytic choriomeningitis virus infections. Here we show the direct ex vivo visualization of mHag-specific CTLs during GvHD using tetrameric HLA-class and I-mHag HA-1 and HY peptide complexes. In the peripheral blood of 17 HA-1 or HY mismatched marrow recipients, HA-1- and HY-specific CTLs were detected as early as 14 days after bone marrow transplantation. The tetrameric complexes demonstrated a significant increase in HA-1- and HY-specific CTLs during acute and chronic GvHD, which decreased after successful GvHD treatment. HLA class I-mHag peptide tetramers may serve as clinical tools for the diagnosis and monitoring of GvHD patients.

T cell responses to D-penicillamine in drug-induced myasthenia gravis: recognition of modified DR1:peptide complexes

The anti-rheumatoid drug D-penicillamine (D-pen) has a reactive sulfhydryl group capable of modifying self antigens, and can provoke typical autoantibody-mediated myasthenia gravis (MG), especially in DR1+ individuals. We have selected T cell clones from one such patient that were highly specific for D-pen but not its L-isomer or D-cysteine. Moreover, they were restricted to HLA-DR1, had a Th1 phenotype and used TCR V alpha4.1, V beta6.1. They responded well to blood mononuclear cells prepulsed with D-pen either in the absence of serum or after chloroquine treatment, but not to autologous D-pen-pulsed B cell lines. Thus, D-pen may directly couple to distinctive peptides resident in surface DR1 molecules on circulating macrophages or dendritic cells.

Molecular cloning and characterization of prostase, an androgen-regulated serine protease with prostate-restricted expression

The identification of genes with selective expression in specific organs or cell types provides an entry point for understanding biological processes that occur uniquely within a particular tissue. Using a subtraction approach designed to identify genes preferentially expressed in specific tissues, we have identified prostase, a human serine protease with prostate-restricted expression. The prostase cDNA encodes a putative 254-aa polypeptide with a conserved serine protease catalytic triad and an amino-terminal pre-propeptide sequence, indicating a potential secretory function. The genomic sequence comprises five exons and four introns and contains multiple copies of a chromosome 19q-specific minisatellite repeat. Northern analysis indicates that prostase mRNA is expressed in hormonally responsive normal and neoplastic prostate epithelial tissues, but not in prostate stromal constituents. Prostase shares 35% amino acid identity with prostate-specific antigen (PSA) and 78% identity with the porcine enamel matrix serine proteinase 1, an enzyme involved in enamel matrix degradation and with a putative role in the disruption of intercellular junctions. Radiation-hybrid-panel mapping localized prostase to chromosome 19q13, a region containing several other serine proteases, including protease M, pancreatic/renal kallikrein hK1, and the prostate-specific kallikreins hK2 and hK3 (PSA). The sequence homology between prostase and other well-characterized serine proteases suggests several potential functional roles for the prostase protein that include the degradation of extracellular matrix and the activation of PSA and other proteases.

Early-onset myasthenia gravis: a recurring T-cell epitope in the adult-specific acetylcholine receptor epsilon subunit presented by the susceptibility allele HLA-DR52a

No immunodominant T-cell epitopes have yet been reported in the human acetylcholine receptor (AChR), the target of the pathogenic autoantibodies in myasthenia gravis (MG). We have selected and characterized T cells from MG patients by restimulation in culture with recombinant human AChR to alpha, gamma and epsilon subunits; the gamma and epsilon distinguish the fetal and adult AChR isoforms, respectively. We obtained clones specific for the epsilon, rather than the alpha or gamma, subunit in 3 of the first 4 early-onset MG cases tested. They all responded to peptide epsilon201-219 and to low concentrations of adult but not fetal AChR. Moreover, although using different T-cell receptor genes, they were all restricted to HLA-DR52a (DRB3*0101), a member of the strongly predisposing HLA-A1-B8-DR3 haplotype. This apparently immunodominant epsilon201-219 epitope (plus DR52a) was also recognized by clones from an elderly patient whose MG had recently been provoked by the drug D-penicillamine. In all 4 cases, however, the serum antibodies reacted better with fetal than adult AChR and may thus be end products of determinant spreading initiated by adult AChR-specific T cell responses. Furthermore, as these T cells had a pathogenic Th1 phenotype, with the potential to induce complement-activating antibodies, they should be important targets for selective immunotherapy.

Decay kinetics of human immunodeficiency virus-specific effector cytotoxic T lymphocytes after combination antiretroviral therapy

Little is known of the changes in human immunodeficiency virus type 1 (HIV-1)-specific effector cytotoxic T lymphocytes (CTL) after potent antiretroviral therapy. Using HLA/peptide tetrameric complexes, we show that after starting treatment, there are early rapid fluctuations in the HIV-1-specific CTL response which last 1 to 2 weeks. These fluctuations are followed by an exponential decay (median half-life, 45 days) of HIV-1-specific CTL which continues while viremia remains undetectable. These data have implications for the immunological control of drug-resistant virus.

New ultraviolet signal actuated switching valve for the measurement of low level impurities by liquid chromatography/mass spectrometry

A new ultraviolet (UV) signal actuated switching valve for diverting the main matrix compound to waste, preventing it entering the ion source of the mass spectrometer is described. Sensitivity for trace impurities eluting after the drug substance cimetidine or related compounds could be enhanced by a factor of 4-5. The increase in sensitivity was dependent on the type of ion source which interfaced the mass spectrometer. The benefit of the switching valve was greater with a line of sight type source than with an orthogonal one. The detection limit for a trace compound in a matrix compound was improved by up to a factor of 10 with the line of sight type source but only by a factor of 5 with the orthogonal source.

A pathogenetic role for the thymoma in myasthenia gravis. Autosensitization of IL-4- producing T cell clones recognizing extracellular acetylcholine receptor epitopes presented by minority class II isotypes

Myasthenia gravis (MG) is caused by helper T cell-dependent autoantibodies against the muscle acetylcholine receptor (AChR). Thymic epithelial tumors (thymomas) occur in 10% of MG patients, but their autoimmunizing potential is unclear. They express mRNAs encoding AChR alpha and epsilon subunits, and might aberrantly select or sensitize developing thymocytes or recirculating peripheral T cells against AChR epitopes. Alternatively, there could be defective self-tolerance induction in the abundant maturing thymocytes that they usually generate. For the first time, we have isolated and characterized AChR-specific T cell clones from two MG thymomas. They recognize extracellular epitopes (alpha75-90 and alpha149-158) which are processed very efficiently from muscle AChR. Both clones express CD4 and CD8alpha, and have a Th-0 cytokine profile, producing IL-4 as well as IFN-gamma. They are restricted to HLA-DP14 and DR52a; expression of these minority isotypes was strong on professional antigen-presenting cells in the donors' tumors, although it is generally weak in the periphery. The two clones' T cell receptor beta chains are different, but their alpha chain sequences are very similar. These resemblances, and the striking contrasts with T cells previously cloned from non-thymoma patients, show that thymomas generate and actively induce specific T cells rather than merely failing to tolerize them against self antigens.

The repertoire of T cell antigen receptor beta-chain variable regions associated with psoriasis vulgaris

We investigated whether the pattern of T-cell receptors expressed by T cells in inflamed psoriatic skin differed substantially from the pattern seen in T cells from the peripheral blood. A bias or restriction in the repertoire of T-cell receptors found in the lesional skin of different patients might imply that specific subsets of T cells were causally associated with initiating or maintaining the lesions. By using a polymerase chain reaction-based assay of T-cell receptor beta-chain variable region mRNA, we found that the patterns of beta-chain mRNAs displayed in 14 samples of lesional skin or six samples of noninvolved skin were not significantly less diverse than the patterns found in matched peripheral blood samples. There was no evidence that the active lesions of multiple patients showed overexpression of T cells expressing one or a few T-cell receptor forms. The pattern of T-cell receptors displayed in clinically normal skin from normal control individuals showed about the same diversity as normal blood. While these results may not exclude either classical antigen or superantigen-based T-cell activation mechanisms in active plaques, the absence of a simple pattern of Vbeta usage in different patients suggests than other aspects of T-cell biology including trafficking, proliferation, co-stimulation, or responses to cytokines must also be considered.

Negotiating spaces in home environments: older women living with arthritis

Within medical geography there has been a surge of interest in applying critical concepts in social theory to empirical settings, including those for persons with disabilities. The ways through which persons with disabilities negotiate space vary widely according to material and social experiences of being disabled. For older women, chronic illness as a type of disability shapes the way in which they approach their daily lives with respect to both the physical and social aspects of their home environments. In the first half of the paper, conceptually, I take a relational view of space and argue that household, as a narrow reading of domestic space, needs to be replaced by home environment which incorporates more fully age- and ablement-sensitive readings of the spaces constitutive of domestic space. This lays the basis for a contextualized socio-spatial understanding of the ways older women with chronic illness negotiate the spaces in home environments because it accounts for the disadvantaged positionings of access to power and resources as well as the uneven distributions of income based on gender, age, and (dis)ability. It also takes into account the material and social aspects of being disabled. In the second half of the paper, I present case studies of three older women diagnosed with rheumatoid arthritis to illustrate these arguments.

Clonal populations of CD4+ and CD8+ T cells in patients with multiple myeloma and paraproteinemia

Patients with paraproteinemia have abnormalities in their T-cell subsets including inversion of the CD4:CD8 ratio and increased expression of activation markers. Recently, distortions in T-cell receptor (TCR) TCRAV and TCRBV gene segment expression have been reported, although the significance of these observations is unclear given the finding of clonal populations of CD8+ T cells in healthy elderly individuals. We have used an extensive range of TCR V-region-specific monoclonal antibodies to assess TCRAV and TCRBV expression in patients with myeloma and paraproteinemia. TCR sequence analysis was used to assess the clonality of expansions and 3-color fluorescence-activated cell sorting analysis determined the phenotype of the expanded populations. The patients show novel oligoclonal expansions within the CD4+ subset and show an increased frequency of CD8+ expansions. Oligoclonal CD4+ T cells belong to the rare CD4+CD28- T-cell subset, a phenotype associated with granular morphology. CD45RA and CD11b are expressed on many of the CD8 T-cell expansions. Comparison of T-cell receptor sequences from two T-cell clones in one patient suggests a possible role for a common peptide antigen in the generation of the expansions. Further work is needed to identify the relevance of such T cells to the B-cell proliferation.

Responses to reduced water intake, including dehydration natriuresis, in sheep excreting sodium predominantly in urine or in faeces

Sheep which were predominantly urinary excretors (U) or faecal excretors (F) of sodium were exposed to a 75% reduction of water intake for 72 h. The experiment was performed on moderate, low or high sodium intakes (0.4, 0.05 or 1.2 mmol kg-1 day-1) to test the hypothesis that dehydration natriuresis was not a cause of sodium depletion but a defence against hypernatraemia. Dehydration caused elevation of plasma sodium concentration, osmolality, antidiuretic hormone (ADH) and oxytocin but, as in other experiments, a fall in haematocrit. The two higher levels of sodium intake were associated with dehydration natriuresis but also a smaller increase in faecal sodium excretion in both U and F sheep. On low sodium intake, however, neither urinary nor faecal sodium excretion increased in either group of sheep although the rise in plasma sodium concentration caused by dehydration was similar. Thus, when there is a risk of sodium depletion, due to low sodium intake, dehydration natriuresis does not occur, consistent with the hypothesis. Active sodium transport inhibitor (ASTI) and atrial natriuretic peptide (ANP) fell rather than rose during dehydration. Since aldosterone is suppressed by the higher levels of sodium intake, none of these hormones is likely to mediate dehydration natriuresis in sheep. F sheep showed more effective renal and faecal water conservation when dehydrated. During water restriction, the urinary potassium excretion of U sheep was significantly reduced, unlike that of F sheep; moreover, the latter maintained an identical plasma potassium concentration between baseline and restriction period, whereas in U sheep it was 0.3 mmol l-1 higher during water restriction. Increased drinking rather than reduced urine output was the basis of rehydration when ad lib. water intake was restored.

Systematic study of human alpha beta T cell receptor V segments shows allelic variations resulting in a large number of distinct T cell receptor haplotypes

The variation of the alpha beta T cell receptor (TCR) results mainly from rearrangements of germ-line V, D and J elements combined with the processes of N- and P-region addition. In addition to this extensive diversity, diallelic polymorphism is also recognized in V regions of beta loci. Four such polymorphisms have previously been defined, but the full extent of such variation has not yet been established. To investigate allelic polymorphism, we used a strategy based V locus-specific polymerase chain reaction and single-strand conformation polymorphisms. Studying the two V beta 2 loci and the V alpha 8.1 locus, we found that all exhibited a coding polymorphism. One of the V beta 2 loci proved to be the first multiallele segment to be recognized, with three common variants. The second V beta 2 locus, for which none of the two alleles has been identified in cDNA, appeared in fact to be a V beta orphon, in abnormal location on the chromosome 9. A yeast artificial chromosome containing part of the TCRB locus allowed us to place the first V beta 2 segment on the known map to define haplotypes with two other polymorphic segments: V beta 1 and V beta 6.7. Multiple distinct haplotypes result from combinations between these polymorphic loci, showing that V beta regions are highly variable between individuals. Two alleles exist at the V alpha 8.1 segment and both are expressed. This represents the first example of a frequent coding polymorphism for TCRA gene. The distribution of allele frequencies for these segments suggest the action of balancing selection. These data add a further dimension to TCR polymorphism and suggest new candidates to explore TCR-encoded susceptibility to autoimmune diseases.

Differences between sheep excreting sodium predominantly in their urine or in their faeces: the effect of changes in sodium intake

Sheep receiving a total of about 31 mmol day-1 (0.5 mmol kg-1) of sodium were classified according to the predominant route of sodium excretion; urinary (U) or faecal (F). U sheep had a greater water turnover than F sheep; their intake was 41% higher and they produced 133% more urine but there was little difference in faecal water loss. Most faecal sodium was readily exchangeable with water in both groups. When sodium intake was reduced by 80% (to 6 mmol day-1; 0.1 mmol kg-1), the reduction in total sodium excretion was equally effective in F sheep and U sheep after 48 h and after 2 weeks the overall losses of sodium were smaller in F sheep. On sodium intakes close to requirement (0.1 mmol kg-1 or less) the majority of the sheep excreted most of their sodium in faeces and did so on intakes up to 0.5 mmol kg-1 day-1. Excess dietary sodium is mainly excreted renally. When sodium intake is increased abruptly (by 20 mmol day-1, 0.3 mmol kg-1), total sodium excretion only increases gradually but after about 3 days it 'overshoots' as in humans.

Salt appetite during pregnancy in sheep

Sodium preference was examined in three groups of sheep which had all sustained two consecutive pregnancies and lactations on either adequate sodium intakes (group C) or low sodium diets (B and C). Group B received a potassium supplement as well as a low sodium diet during the present experiment. No convincing or sustained increase in sodium preference resulted from the reduction in body sodium caused by pregnancy and lactation in group B or C, whether the sodium solutions offered were 40 or 300 mmol/l. In a second experiment, sodium preference (sodium bicarbonate, 40 mmol/l) was studied throughout pregnancy in sheep on low or adequate sodium diets, also non-pregnant controls on low sodium diets. Again, pregnancy on a low sodium intake failed to intensify salt appetite except for a transient (but significant) peak around d90, close to the peak of aldosterone secretion; a similar increase in preference occurred on the adequate sodium diet. However, salt appetite failed to intensify during the period of peak sodium demand (the last third of pregnancy) whereas renal and faecal sodium conservation are appropriately increased.

The hospital inpatient stay: the experience of first-time parents

The experience of hospital inpatient stays at childbirth was studied in a longitudinal study of the experiences of 96 first-time parents during the transition to parenthood. For women, the prospect of birth was a major worry during pregnancy. Negative expectations proved in general to be justified by events, with many women reporting predominantly bad memories of the experience. Satisfaction with the hospital inpatient stay is also considered: a major source of dissatisfaction was inadequate help with breast feeding, which produced many difficulties. Middle class mothers were in general more dissatisfied with their hospital stay, as were women who had Caesarean births. Relationships were found between antenatal class attendances and the likelihood of a normal delivery and reported pain during childbirth. The role and experience of fathers was also considered. Most expected to be at the birth from an early stage in pregnancy; more than two-thirds were present for the delivery and half or more at the labour. Their experience at this time was more positive than that of their partners. But during the hospital stay, this role was much more marginal. The results are discussed in terms of their implications for antenatal preparation, breast feeding and paternal involvement.

Prolongation of lidocaine spinal anesthesia with phenylephrine

The effect of added phenylephrine on the duration of sensory analgesia during lidocaine spinal anesthesia was determined in 65 ASA class I-III patients randomly divided into three groups. Group 1 (n = 25) received 62.5 mg lidocaine in 7.5% glucose; group 2 (n = 21) received lidocaine with 2 mg phenylephrine; and group 3 (n = 19) received lidocaine with 5 mg phenylephrine. The level of analgesia to pin prick was assessed by an anesthesiologist unaware of the drug combination used. The mean +/- SD cephalad level of analgesia did not differ among the groups. In group 1, the times for two- and for four-segment regression of the level of analgesia, and the time for regression of analgesia to the T-12 dermatome, were 77 +/- 19 (1 SD), 99 +/- 24, and 109 +/- 26 min, respectively. The corresponding values were 98 +/- 25, 118 +/- 27, and 130 +/- 36 min in group 2 and 124 +/- 32, 142 +/- 31, and 162 +/- 35 min in group 3. All the regression times in group 2 were significantly longer than those in group 1 (P less than 0.05). All the regression times in group 3 were significantly longer than those in group 2 (P less than 0.02). It is concluded that clinically useful prolongation of sensory analgesia may be obtained by addition of phenylephrine to lidocaine during spinal anesthesia.

Altered synthesis of myosin light chains is associated with contractility in cultures of differentiating chick embryo breast muscle

Cultured chick embryo skeletal muscle cells normally synthesize only the embryonic isoform of mysoin. We have found that aneural muscle cultures that become or are provoked into an extremely contractile state will begin to synthesize a pattern of myosin light chains typical of maturing muscle. Immunoblots with neonatal and adult specific monoclonal antibodies did not reveal a corresponding isozyme transition in myosin heavy chain. These results demonstrate a correlation between contractility and the regulation of myosin light chain maturation, and also suggest that the transitions of heavy and light chain synthesis during development do not appear to be under close coordinate regulation.

Effect of induced hypomagnesaemia on the toxicity of imidocarb in calves

The hypothesis that the toxic effects of imidocarb mediated by reduced cholinesterase activity might be intensified by hypomagnesaemia was tested in calves. Hypomagnesaemia was induced in 12 males (50 kg) using an artificial milk based on a commercial nondairy coffee creamer. Although plasma magnesium levels reached 0.33 mmol litre-1 in two weeks no clinical signs were detected. In 12 control calves a daily magnesium supplement of 0.6 g was inadequate although the published requirement is 0.45 g; it was raised to 1.2 g to keep plasma magnesium normal. Lighter calves developed hypomagnesaemia more readily and fast-growing calves had lower plasma urea concentrations. Plasma calcium, but not plasma magnesium, showed significant positive correlation with plasma albumin. The only statistically significant effects of hypomagnesaemia were slight elevations of white cell count and plasma sodium. The hypomagnesaemic and normomagnesaemic calves were divided into two equal groups and treated with 3.3 mg kg-1 of imidocarb dipropionate or a placebo. The drug produced the expected clinical signs of mild toxicity and depression of cholinesterase but no other adverse effects. Transient slight depressions of plasma calcium and potassium concentration, a transient rise of plasma sodium and elevation of creatine kinase occurred. None of the effects of imidocarb treatment was intensified by hypomagnesaemia except, perhaps, constriction of the pupils; generally, hypomagnesaemic animals were affected less.

Cellular localization of the transforming protein of wild-type and temperature-sensitive Fujinami sarcoma virus

Fujinami sarcoma virus (FSV) encodes a 140,000-dalton transforming protein, P140, which contains gag- and fps-specific sequences. The cellular localization of this protein was examined by fractionation of [35S]methionine-labeled, FSV-infected chicken embryo fibroblasts. In homogenates of cells infected by wild-type, temperature-resistant FSV prepared in either hypotonic or isotonic buffer, 60 to 80% of the P140 was particulate. Isopycnic separation on discontinuous sucrose gradients indicated that the majority of the particulate P140 was present in a light membrane fraction enriched for plasma membranes. Much of the particulate P140 could be solubilized by the addition of 0.6 M salt to a postnuclear supernatant, suggesting that P140 is not an integral membrane protein. Particulate P140 may be associated with membranes either directly as a peripheral membrane protein or indirectly via cytoskeletal elements. In cells infected by mutants of FSV temperature sensitive for cellular transformation, most of the P140 is particulate at the permissive temperature, whereas most is soluble at the nonpermissive temperature; this change in distribution is not a secondary consequence of the change in cellular phenotype, since it also occurs in nonconditionally transformed cells doubly infected with temperature-sensitive FSV and wild-type Rous sarcoma virus. The movement of P140 from the particulate to the soluble fraction occurs rapidly when cells infected by temperature-sensitive FSV are shifted from the permissive to the nonpermissive temperature. Furthermore, P140 moves from the soluble to the particulate fraction, although somewhat more slowly, when cells are shifted from the nonpermissive to the permissive temperature. These observations suggest that the association of P140 with plasma membranes or the cytoskeleton may play a role in transformation by FSV.

The role of protein phosphorylation at tyrosine in transformation and mitogenesis

In cells transformed by avian sarcoma viruses or stimulated by growth factors, certain polypeptides become phosphorylated at tyrosine residues. It is not known if these cellular polypeptides are phosphorylated directly by the tyrosine-kinase activities which are associated with the viral transforming proteins and with growth factor receptors. It is also not clear if phosphorylation of these polypeptides is required for viral transformation or the response to growth factors. We describe here some observations which bear on these questions and discuss possible future approaches.

Membrane association of a 36,000-dalton substrate for tyrosine phosphorylation in chicken embryo fibroblasts transformed by avian sarcoma viruses

A cellular protein of 36,000 daltons becomes phosphorylated at tyrosine in chicken embryo fibroblasts transformed with avian sarcoma viruses. We have used cellular fractionation and immunofluorescence to locate the 36-kdalton protein in virus-transformed and uninfected chicken fibroblasts. The 36-kdalton protein in transformed cells fractionated mainly with high-speed particulate material, and in density gradient separations, the 36-kdalton protein was found in association with light density membranes together with most of the plasma membrane marker. Increasing the concentration of salt or adding ion chelators solubilized some of the 36-kdalton protein that otherwise was pelletable with high g forces. Based on these data, we conclude that this protein is peripherally or indirectly attached to light density membranes, including plasma membranes. Indirect immunofluorescent staining of the 36-kdalton protein in fixed cells revealed that it was located inside the cell in an extensive reticulum apposed to surface membranes. The same pattern of staining was found in both uninfected and virus-transformed cells. Pretreatment of cells with nonionic detergents before fixation altered or abolished 36-kdalton staining. The 36-kdalton protein appeared to be excluded from regions of the cells where actin cables were present. The pattern of staining observed with the anti-36-kdalton antibody was similar, but not identical, to that observed with antiserum against nonerythroid spectrin. Thus, the data obtained by biochemical fractionation and by immunofluorescent staining indicate that the 36-kdalton protein is found in a reticulum at the inner surface of the plasma membrane, possibly in association with cytoskeletal proteins.

Mental distress in mothers of pre-school children in inner London

The level of mental 'distress' was assessed for a sample of mothers with pre-school children in Inner London. Fifty-two per cent of mothers had a moderate or severe distress problem in the 12 months prior to interview. Variables correlating with distress were identified and replicated in a second sample. Social class was not found to be related, and the question of the general relationship between social class and distress is considered.

Bacterial metabolism of 4-chlorophenoxyacetate

1. A pseudomonad capable of utilizing 4-chlorophenoxyacetate (CPA) as sole source of organic carbon was isolated from soil. 2. The organism was grown in liquid culture and the following compounds were isolated and identified in culture extracts: 4-chloro-2-hydroxyphenoxyacetate, 4-chlorocatechol, beta-chloromuconate probably the cis-trans isomer and gamma-carboxymethylene-Delta(alphabeta)-butenolide. 3. Cells grown on 4-chlorophenoxyacetate were able to metabolize 4-chloro-2-hydroxyphenoxyacetate, 4-chlorocatechol and gamma-carboxymethylene-Delta(alphabeta)-butenolide without a lag period. They were not adapted to 4-chlorophenol, or to either culture isolated or synthetic beta-chloromuconate, possibly because of stereospecificity towards the cis-cis isomer. 4. On the basis of isolation and induction evidence, the following metabolic pathway is proposed for the breakdown of 4-chlorophenoxyacetate by this organism: 4-chlorophenoxyacetate --> 4-chloro-2-hydroxyphenoxyacetate --> 4-chlorocatechol --> cis-cis-beta-chloromuconate --> gamma-carboxymethylene-Delta(alphabeta)-butenolide --> maleylacetate and fumarylacetate --> fumarate and acetate.