Novel, cross-restricted, conserved, and immunodominant cytotoxic T lymphocyte epitopes in slow progressors in HIV type 1 infection

HIV-specific cytotoxic T lymphocytes (CTLs) play an important role in the immune response to HIV infection. Long-term nonprogressors (LTNPs) or slow progressors (SPs) in HIV infection may make qualitatively different CTL responses compared to those generated by seropositive individuals who progress to disease at a faster rate. The class I molecule HLA-B*57 has been identified as one restriction element overrepresented in SP groups studied, and, together with the closely related molecule HLA-B*58, occurs commonly in ethnic groups where HIV is most prevalent. In this study, we have identified five new HLA-B*57-restricted CTL epitopes recognized by SP donors, one of which is also HLA-B*5801 restricted. These HLA-B*57-restricted responses represent the dominant HIV-specific CTL response in each of the SP donors tested. These and other such epitopes may be an important component in future vaccine design.

Neuroinvasion and persistence of human herpesvirus 6 in children

Human herpesvirus 6 (HHV-6) causes a febrile illness in children and has been implicated as a cause of encephalitis and recurrent seizures. Paired samples of cerebrospinal fluid (CSF) and peripheral blood mononuclear cells (PBMC) from 487 children were evaluated by nested polymerase chain reaction (PCR) for evidence of current or past infection with HHV-6. PBMC were also cultured for isolation of HHV-6. These data were correlated with the patients' clinical information. HHV-6 DNA was detected in 72 (14.8%) of 487 CSF samples. HHV-6 persistence was documented in 142 children by PCR detection of HHV-6 DNA in PBMC or CSF (or both) in the absence of primary HHV-6 infection; the central nervous system was the only site of HHV-6 DNA persistence in 28.9%. HHV-6 DNA can be detected in the CSF of children during and after primary infection, and the central nervous system may be the sole site of persistence.

Primary human herpesvirus 6 infection in young children

BACKGROUND

Human herpesvirus 6 (HHV-6) is a recently discovered virus that, on the basis of serologic evidence, appears to infect most children by the age of three years. However, the clinical manifestations of primary HHV-6 infection have not been well defined.

METHODS

We studied consecutive children two years old or younger who presented to an emergency ward with febrile illnesses. Our evaluation included the isolation of HHV-6 from peripheral-blood mononuclear cells, an immunofluorescent-antibody assay, the detection of HHV-6 by the polymerase chain reaction (PCR), and restriction-endonuclease-fragment profiles of HHV-6 isolates.

RESULTS

HHV-6 was isolated from 34 of 243 acutely ill children (14 percent). The children with viremia had irritability, high temperatures (mean, 39.7 degrees C), and inflammation of tympanic membranes (in 21), but few other localizing signs. Two children were hospitalized, but all 34 recovered after an average of four days of fever. The rash characteristic of roseola, which has been associated with HHV-6 infection, was noted in only three children. In 29 children (85 percent), serum samples obtained during convalescence had at least a fourfold increase in IgG antibody titers; 4 infants less than three months old who presumably had maternal antibody did not have this increase. HHV-6 was isolated from blood obtained during convalescence in only one child, but in two thirds of the children the virus could be detected by PCR. The isolates had genomic heterogeneity, indicating the presence of multiple strains.

CONCLUSIONS

Primary infection with HHV-6 is a major cause of acute febrile illness in young children. Such infection is associated with varied clinical manifestations, viremia, and the frequent persistence of the viral genome in mononuclear cells.

Human herpesvirus 6 (HHV-6) variant B accounts for the majority of symptomatic primary HHV-6 infections in a population of U.S. infants

Two variants of human herpesvirus 6 were identified. To assess their epidemiology and disease association, we analyzed viral isolates and/or uncultured peripheral blood mononuclear cells from 76 infants with symptomatic primary infection. In 97% of cases, human herpesvirus 6 variant B was detected, but variant A was not.

Internet cognitive behavioural therapy for mixed anxiety and depression: a randomized controlled trial and evidence of effectiveness in primary care

BACKGROUND

Major depressive disorder (MDD) and generalized anxiety disorder (GAD) have the highest co-morbidity rates within the internalizing disorders cluster, yet no Internet-based cognitive behavioural therapy (iCBT) programme exists for their combined treatment.

METHOD

We designed a six-lesson therapist-assisted iCBT programme for mixed anxiety and depression. Study 1 was a randomized controlled trial (RCT) comparing the iCBT programme (n = 46) versus wait-list control (WLC; n = 53) for patients diagnosed by structured clinical interview with MDD, GAD or co-morbid GAD/MDD. Primary outcome measures were the Patient Health Questionnaire nine-item scale (depression), Generalized Anxiety Disorder seven-item scale (generalized anxiety), Kessler 10-item Psychological Distress scale (distress) and 12-item World Health Organization Disability Assessment Schedule II (disability). The iCBT group was followed up at 3 months post-treatment. In study 2, we investigated the adherence to, and efficacy of the same programme in a primary care setting, where patients (n = 136) completed the programme under the supervision of primary care clinicians.

RESULTS

The RCT showed that the iCBT programme was more effective than WLC, with large within- and between-groups effect sizes found (>0.8). Adherence was also high (89%), and gains were maintained at 3-month follow-up. In study 2 in primary care, adherence to the iCBT programme was low (41%), yet effect sizes were large (>0.8). Of the non-completers, 30% experienced benefit.

CONCLUSIONS

Together, the results show that iCBT is effective and adherence is high in research settings, but there is a problem of adherence when translated into the 'real world'. Future efforts need to be placed on developing improved adherence to iCBT in primary care settings.

Murine I-A beta chain polymorphism: nucleotide sequences of three allelic I-A beta genes

The polymorphism of immune response genes plays a critical role in determining the immune capabilities of a particular individual. The molecular nature of this polymorphism was studied by examining the structure of the coding portions of three alleles of the I-A beta chain gene, an immune response gene whose protein product constitutes a subunit of the I-A molecule. Comparison of the I-A beta chains encoded by these alleles revealed an amino acid sequence divergence of 5 to 8 percent. The differences were found to be a series of short alterations clustered in the amino terminal half of the polypeptide.

Long-term efficacy and safety of addition of carboplatin with or without veliparib to standard neoadjuvant chemotherapy in triple-negative breast cancer: 4-year follow-up data from BrighTNess, a randomized phase 3 trial

BACKGROUND

Primary analyses of the phase 3 BrighTNess trial showed addition of carboplatin with/without veliparib to neoadjuvant chemotherapy significantly improved pathological complete response (pCR) rates with manageable acute toxicity in patients with triple-negative breast cancer (TNBC). Here, we report 4.5-year follow-up data from the trial.

DESIGN

Women with untreated stage II-III TNBC were randomized (2:1:1) to paclitaxel (weekly for 12 doses) plus either: (a) carboplatin (every 3 weeks for four cycles) plus veliparib (twice daily); (b) carboplatin plus veliparib placebo; or (c) carboplatin placebo plus veliparib placebo. All patients then received doxorubicin and cyclophosphamide (AC) every 2‒3 weeks for four cycles. The primary endpoint was pCR. Secondary endpoints included event-free survival (EFS), overall survival (OS), and safety. Since the co-primary endpoint of increased pCR with carboplatin plus veliparib with paclitaxel versus carboplatin with paclitaxel was not met, secondary analyses are descriptive.

RESULTS

Of 634 patients, 316 were randomized to carboplatin plus veliparib with paclitaxel, 160 to carboplatin with paclitaxel, and 158 to paclitaxel. With median follow-up of 4.5 years, the hazard ratio [HR] for EFS for carboplatin plus veliparib with paclitaxel versus paclitaxel was 0.63 (95% confidence interval [CI] 0.43‒0.92, P=0.02), but 1.12 (95% CI 0.72‒1.72, P=0.62) for carboplatin plus veliparib with paclitaxel versus carboplatin with paclitaxel. In post hoc analysis, HR for EFS was 0.57 (95% CI 0.36‒0.91, P=0.02) for carboplatin with paclitaxel versus paclitaxel. OS did not differ significantly between treatment arms, nor did rates of myelodysplastic syndromes, acute myeloid leukemia, or other secondary malignancies.

CONCLUSION

Improvement in pCR with addition of carboplatin was associated with long-term EFS benefit with a manageable safety profile, and without increasing the risk of second malignancies, while adding veliparib did not impact EFS. These findings support the addition of carboplatin to weekly paclitaxel followed by AC neoadjuvant chemotherapy for early stage TNBC.

Effect of aerobic exercise on cognition in younger adults: A randomized clinical trial

OBJECTIVE

To determine efficacy of aerobic exercise for cognitive function in younger healthy adults.

METHODS

In a randomized, parallel-group, observer-masked, community-based clinical trial, 132 cognitively normal individuals aged 20-67 with below median aerobic capacity were randomly assigned to one of two 6-month, 4-times-weekly conditions: aerobic exercise and stretching/toning. Efficacy measures included aerobic capacity; cognitive function in several domains (executive function, episodic memory, processing speed, language, and attention), everyday function, body mass index (BMI), and cortical thickness.

RESULTS

Aerobic capacity increased significantly (β = 2.718; p = 0.003), and BMI decreased significantly (β = -0.596; p = 0.013) in the aerobic exercise but not in the stretching/toning condition. Executive function improved significantly in the aerobic exercise condition; this effect was moderated by age (β = 0.018 SD/y; p = 0.028). At age 40, the executive function measure increased by 0.228 SD (95% confidence interval [CI] 0.007-0.448), and by 0.596 SD (95% CI 0.219-0.973) at age 60. Cortical thickness increased significantly in the aerobic exercise group in a left frontal region and did not interact with age. Controlling for age and baseline performance, individuals with at least one APOE ε4 allele showed less improvement in executive function with aerobic exercise (β = 0.5129, 95% CI 0.0381-0.988; p = 0.0346).

CONCLUSIONS

This randomized clinical trial demonstrates the efficacy of aerobic exercise for cognition in adults age 20-67. The effect of aerobic exercise on executive function was more pronounced as age increased, suggesting that it may mitigate age-related declines. Increased cortical thickness suggests that aerobic exercise contributes to brain health in individuals as young as age 20.

CLINICALTRIALSGOV IDENTIFIER

NCT01179958.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that for adults age 20-67 with below median aerobic capacity, aerobic exercise significantly improves executive function but not other measures of cognitive function.

Evaluation of Simulated Presence: a personalized approach to enhance well-being in persons with Alzheimer's disease

OBJECTIVE

To evaluate the efficacy of Simulated Presence, a personalized approach to enhance well-being among nursing home residents with Alzheimer's disease and related dementia's (ADRD).

DESIGN

Latin-Square, double blinded, 3-factor design with restrictive randomization of three treatments (the study intervention, a placebo audio tape of a person reading the newspaper, and usual care). The three factors were treatment, time, and facility type.

SETTING

Nine nursing homes in Eastern Massachusetts and Southern New Hampshire.

PARTICIPANTS

Fifty-four subjects with documented ADRD who were aged 50 years or older, medically stable, had resided in their current nursing home for at least 3 months, and who had no planned discharge. All subjects had a history of agitated or withdrawn behaviors.

INTERVENTION

The purpose of Simulated Presence is to provide a personalized intervention for persons with moderate to severe cognitive impairment. Through a unique testing process, some of the best loved memories of the ADRD person's lifetime are identified and then those memories are introduced to the patient in the format of a telephone conversation using a continuous play audio tape system. The intervention may be used for extended periods of time because each repetition is viewed as a fresh, live telephone call as a result of the short-term memory deficit of the person with ADRD.

MEASUREMENTS

Direct observations of outcomes included using a newly developed scale, the Scale for the Observation of Agitation in Persons with Dementia, an agitation visual analog scale, the Positive Affect Rating Scale (mood and "interest"), a withdrawal visual analog scale, and facial diagrams of mood. Reported measures included daily staff observation logs of responses to interventions offered, and weekly staff surveys using the short-form Cohen-Mansfield Agitation Inventory and the Multidimensional Observation Scale for Elderly Subjects (mood and "interest"). Severity of dementia was assessed by the Mini-Mental State Exam, the Test for Severe Impairment, the Bedford Alzheimer's Nursing Scale, and the ADL Self-Performance Scale.

RESULTS

Chi-square analysis of direct observations, using facial diagrams, revealed that Simulated Presence was equivalent to usual care (P = .141) and superior to placebo for producing a happy facial expression (P = .001). A positive effect was also documented in nursing staff observation logs using Analysis of Variance techniques (ANOVA) for subjects during Simulated Presence phases compared with the placebo phases (P < .001) and usual care phases (P < .001). According to ANOVA analyses of "interest" from weekly surveys, Simulated Presence was superior to both usual care (P = .001) and placebo (P = .008). We were unable to find evidence of significant differences (P < .05) among interventions for other direct observations and weekly reports of overall agitation or mood aspects of withdrawal. Subjects accepted the intervention most of the time, except for five subjects who refused it more than 50% of the time.

CONCLUSION

This study provided evidence that Simulated Presence can be effective in enhancing well-being and decreasing problem behaviors in the nursing home setting as a substitute for or complement to usual care.

X-ray structure analysis of the iron-dependent superoxide dismutase from Mycobacterium tuberculosis at 2.0 Angstroms resolution reveals novel dimer-dimer interactions

The X-ray structure of the tetrameric iron-dependent superoxide dismutase from Mycobacterium tuberculosis has been refined to an R-factor of 0.167 and a correlation coefficient of 0.954 at 2.0 A resolution. The crystals are monoclinic P2(1) and have four subunits related by strong non-crystallographic 222 (or D2) symmetry in the asymmetric unit. 198 of the 207 amino acids of each subunit are defined by the electron density which shows that they adopt the conserved fold of other iron- or manganese-dependent SODs. The structure can be divided into two domains, the N-terminal domain involving an extended region followed by two projecting antiparallel alpha-helices, and the C-terminal domain containing four more helical segments with a three-stranded antiparallel beta-sheet inserted sequentially between the fourth and fifth helices. The catalytic iron is co-ordinated by five ligands: three histidines (residues 28, 76 and 164), one aspartate (160) and a solvent molecule. The inferred positions of protons at the active site are consistent with the solvent ligand being a hydroxide ion. This ligand interacts with His145 in the Mycobacterium tuberculosis SOD. In the highly homologous Mycobacterium leprae Mn-SOD, the histidine is replaced by glutamine, this being the only significant residue difference within 10 A of the Fe3+. The nature of the amino acid at this position may influence the metal ion specificity of these enzymes. The subunits of the Mycobacterium tuberculosis SOD associate by polar contacts to form dimers, which closely resemble those of other dimeric or tetrameric Fe- or Mn-SODs. However, the dimer-dimer interactions within the tetramer are novel, being dominated by dimerisation of the 144 to 152 loop regions which connect the outer two beta-strands of the three-membered beta-sheet. This contrasts strongly with the other tetrameric Fe- or Mn-SODs where the dimer-dimer association is dominated by the projecting alpha alpha-turn in the N-terminal domain.

Phenotypic and genetic polymorphisms among human herpesvirus-6 isolates from North American infants

Fifteen human herpesvirus-6 (HHV-6) isolates from North American infants with primary infection manifest as febrile or roseola (exanthem subitum) like illnesses were characterized phenotypically on the basis of their in vitro growth in continuous T-cell lines and primary human mononuclear cells and by their reactivity with monoclonal antibodies. All isolates replicated efficiently in primary human cord blood mononuclear cells, but five distinct patterns of viral replication in human cells lines were observed. Two of the HHV-6 isolates from infants were found to replicate in HSB-2 cells, a property associated with so-called group A viruses, which had previously been isolated only from adults. These same isolates also reacted with a panel of A-specific monoclonal antibodies. Genomic characterization of viral isolates using well-characterized restriction site polymorphisms indicated that these two isolates contained a mixture of both A- and B-type genomes, in different proportions. These data suggest that not all HHV-6 isolates can be categorized into one of two broad groups and that such segregation of HHV-6 isolates may in fact be misleading.

In-patient psychiatric care: the patient's view

Little attention has been paid to psychiatric patients' views on their treatment in the medical literature. We carried out a consumer survey of 99 in-patients at an inner London psychiatric hospital. Patients were asked to rate 10 non-treatment and treatment items. Most highly regarded was being free to leave the ward. Of the treatment items, talking to a member of staff was found to be most helpful. The relationships between different items and patient variables such as voluntary versus involuntary status, age and diagnosis are discussed. Sex and number of previous admissions exerted only minor effects. The results are compared with other studies and more work in this area is recommended in order to improve hospital care.

Reproduction in mice lacking a functional type 1 IL-1 receptor

Growth factors and cytokines have been identified in having critical roles at mediating maternal-fetal interactions during pregnancy, with interleukin-1 being a recently implicated factor. Previous experiments indicated that repeated intraperitoneal injections of the Il-1 receptor antagonist (Il-1Ra), which inhibits binding of interleukin-1 (Il-1) to the type 1 Il-1 receptor (Il-1Rt1) blocks blastocyst implantation in superovulated mice. To gain a greater insight into the role of Il-1 receptor in implantation, we analyzed the reproduction of mice deficient for the Il-1Rt1. Our results show that mice lacking this receptor do not exhibit any profound alterations in their reproduction, apart from a slight reduction in mean litter size. Furthermore, repeated intraperitoneal injections of either IL-1Ra or the monoclonal antibody 35F5, which also blocks ligand binding to the Il-1Rt1, did not affect embryo implantation in either wild type and Il-1 receptor deficient mice.

Calcium function in affective disorders and healthy controls

Calcium metabolism has been reported to be disturbed in some forms of affective disorder. We studied concurrently a battery of calcium measures in 29 unipolar, 14 bipolar depressed, 11 manic, and 10 healthy control subjects. In addition to measures of extracellular calcium, we studied intracellular calcium concentration in platelets and measures that reflect cellular capability to maintain a low intracellular Ca++ concentration in red blood cells (RBCs) and platelets. Plasma calcium was lower in unipolar and manic patients than in control subjects. Platelet calcium concentration was lower in unipolar than bipolar depressed patients. RBC Ca++ adenosine triphosphatase (ATPase) was lower in unipolar and control subjects than in bipolar depressed and manic patients. Platelet Ca++ ATPase and Ca++ uptake were inversely correlated with severity of illness in unipolar patients. In bipolar depressed patients, RBC Ca++ ATPase and platelet Ca++ uptake were inversely correlated with severity. In addition to indicating abnormalities in calcium activity in affective disorders, the data suggest that unipolar and bipolar patients differ in several measures and may have different pathophysiological disturbances in calcium metabolism.

The Saccharomyces cerevisiae MUM2 gene interacts with the DNA replication machinery and is required for meiotic levels of double strand breaks

The Saccharomyces cerevisiae MUM2 gene is essential for meiotic, but not mitotic, DNA replication and thus sporulation. Genetic interactions between MUM2 and a component of the origin recognition complex and polymerase alpha-primase suggest that MUM2 influences the function of the DNA replication machinery. Early meiotic gene expression is induced to a much greater extent in mum2 cells than in meiotic cells treated with the DNA synthesis inhibitor hydroxyurea. This result indicates that the mum2 meiotic arrest is downstream of the arrest induced by hydroxyurea and suggests that DNA synthesis is initiated in the mutant. Genetic analyses indicate that the recombination that occurs in mum2 mutants is dependent on the normal recombination machinery and on synaptonemal complex components and therefore is not a consequence of lesions created by incompletely replicated DNA. Both meiotic ectopic and allelic recombination are similarly reduced in the mum2 mutant, and the levels are consistent with the levels of meiosis-specific DSBs that are generated. Cytological analyses of mum2 mutants show that chromosome pairing and synapsis occur, although at reduced levels compared to wild type. Given the near-wild-type levels of meiotic gene expression, pairing, and synapsis, we suggest that the reduction in DNA replication is directly responsible for the reduced level of DSBs and meiotic recombination.

Endoscopic management of benign and malignant biliary strictures

BACKGROUND

It is now possible to manage most extrahepatic bile duct strictures, benign or malignant, using endoscopic retrograde cholangiopancreatography (ERCP) with endoscopic dilatation and stenting.

METHODS

Over a 5-year period we treated 218 patients with strictures of extrahepatic bile ducts. Eighty-six patients had benign biliary stricture. Endoscopic treatment was performed in 67 (78%) of these patients. Open surgical biliary drainage was preferred in 12 patients (14%), and 7 patients (8%) were managed conservatively without stenting or surgery. One hundred and thirty-two patients had malignant biliary stricture. One hundred and one patients (77%) underwent endoscopic stent placement. Thirty-one patients (23%) underwent surgery for potential curative resection after diagnostic ERCP. The average life span in the malignant stricture group was 5 months (range 0.1 to 25 months) after the initial endoscopic procedure.

RESULTS

Altogether 313 endoscopic procedures in 218 patients were performed for benign and malignant bile duct strictures. Complications included hemorrhage in 8 (3%), pancreatitis in 10 (3%), and suspected retroperitoneal perforation in 2 (0.6%). There were no ERCP related deaths; one patient died of uncontrolled bleeding from transhepatic stenting. In benign strictures, there has been no recurrence of strictures after the last stent removal with a mean followup of 21 months (range 0.1 to 31 months). All complications were successfully treated conservatively.

CONCLUSIONS

Endoscopic management of benign and malignant biliary stricture is possible with minimal morbidity and mortality and should be considered an acceptable option to surgical management.

Calcium channel antagonists modulate the acrosome reaction but not capacitation in mouse spermatozoa

Mouse spermatozoa require micromolar concentrations of calcium for capacitation but millimolar levels to initiate an acrosome reaction. Sperm suspensions were capacitated by incubation for 120 min in modified Tyrode's medium containing 90 microM-CaCl2 and then verapamil (0.5-50 microM) or nifedipine (0.1-100 nM), drugs shown to inhibit voltage-sensitive calcium channels in other cell types, was added before the introduction of 1.80 mM-CaCl2. Verapamil at 5-50 microM and nifedipine at 1-100 nM significantly inhibited the calcium-stimulated acrosome reaction response, relative to the drug-free control samples. The possibility that these compounds might inhibit calcium entry during capacitation was examined by incubating suspensions for 120 min in medium containing 90 microM-CaCl2 plus either 5 microM-verapamil or 1 nM-nifedipine, diluting to reduce drug concentration to one-tenth and then adding 1.80 mM-CaCl2. The considerable acrosome reaction response obtained indicated that spermatozoa had undergone capacitation and were able to respond to calcium, despite the continuous presence of calcium channel antagonist at a concentration able to inhibit the response at the end of capacitation. In-vitro fertilization studies indicated that both drugs significantly decreased ability of the spermatozoa to fertilize eggs, consistent with acrosome reaction data. However, results indicated that 50 microM-verapamil was able to induce initial stages of egg activation and thus prevent sperm-egg fusion in zona-intact eggs. The addition of verapamil or nifedipine to suspensions capacitated for 120 min in 1.80 mM-CaCl2 significantly potentiated the acrosome reaction response, compared with drug-free controls. Similar treatment of suspensions incubated for only 30 min, and hence only partly capacitated, failed to evoke a response. The potentiation of the acrosome reaction response by verapamil in cells capacitated in high calcium may indicate either retention, due to the action of antagonists, of released intracellular calcium stores, resulting in intracellular calcium concentrations above the threshold required to trigger the acrosome reaction or action of an activated guanine nucleotide binding (G) protein to produce an agonistic rather than an antagonistic response. These results suggest that calcium channels similar to those termed voltage-sensitive in other cell types may exist and play an important role in calcium movements at the end of capacitation, but not during earlier phases of capacitation.

Substantial between-hospital variation in outcome following first emergency admission for heart failure

BACKGROUND

Following hospitalization with a range of cardiovascular disorders, substantial variation has been noted in clinical outcome, both between and within countries.

OBJECTIVES

To examine the variation, between hospitals, in the clinical outcomes of death and readmission following hospitalization with heart failure in Scotland. Setting All 29 acute hospitals in Scotland with more than 200 beds.

PATIENTS

All 31 452 patients discharged from these hospitals between January 1990 and December 1995 with a first-ever, primary, diagnosis at discharge/death of heart failure.

ANALYSIS

An analysis of the Scottish database of discharge summaries linking index admissions with subsequent admissions and deaths. Death rates and readmission rates were adjusted for baseline age, co-morbidity and socio-economic status and were calculated at different time periods (inpatient, 30 days, 1 year). Rates were calculated separately for large teaching hospitals (n=6, category A), large general hospitals with specialist units (n=8, category B) and medium sized general hospitals with limited specialist units (n=15 category C).

RESULTS

A total of 31 452 patients were discharged between 1990-1995 - 10 219 (33%), 9735 (31%) and 11 498 (37%) to category A, B and C hospitals, respectively. The national, average, inpatient case fatality rate was 15.3%, ranging, in individual hospitals, from the lowest rate of 8.5% to the highest rate of 23.4%. The average 1 year case fatality rate was 42.4%, ranging between 35.3% and 50.8%. A similar two- to threefold variation was found in hospital readmission rates - thus the average 30 day readmission rate was 5.3% (lowest 3.3%, highest 7.3%). This variation, in both case-fatality and readmission rates, was apparent within all three groups of hospitals and persisted after adjustment for the baseline factors outlined above.

CONCLUSIONS

A patient admitted to one Scottish hospital with heart failure may be two to three times more likely to die or be readmitted, both in the short and longer term, compared to a patient admitted to another hospital. Although we may not have accounted for some sources of variation, it is both surprising and disturbing that large, statistically significant, differences in adjusted death and readmission rates can apparently exist for such an important condition in a relatively small country with generally homogenous health care provision. Further, detailed investigation of this apparent variation is required.

Burn injury enhances alveolar macrophage endotoxin sensitivity

Systemic activation of inflammatory cascades has been implicated in the pathogenesis of the multiple organ dysfunction syndrome. To begin to determine whether dysregulation of macrophage cytokine expression after burn plays a role in organ failure, we examined tumor necrosis factor alpha bioactivity of liver and lung macrophages under two conditions: (1) at 1, 3, 5, and 7 days after 40% scald burn, and (2) after sequential insult consisting of 40% scald burn followed by in vitro incubation with endotoxin. Burn alone did not significantly alter alveolar macrophage or Kupffer cell tumor necrosis factor alpha bioactivity at any of the timepoints examined. Sequential insult did not result in significant changes in Kupffer cell tumor necrosis factor alpha, but tumor necrosis factor alpha was increased 11.1 times in alveolar macrophages harvested on postburn day 3. Therefore macrophage cytokine responses to thermal injury are apparently both tissue-specific and time-dependent.

Differential TNF secretion by wound fibroblasts compared to normal fibroblasts in response to LPS

Fibroblasts cultured from wound sites have been shown to have an altered phenotype compared to normal dermal fibroblasts and are generally regarded as target cells of the cytokine response at sites of injury. This study was undertaken to determine whether wound fibroblasts can contribute to proinflammatory cytokine production in wounds and, in particular, whether they are capable of secreting TNF. Wound fibroblasts were cultured from polyvinyl alcohol sponges implanted subcutaneously for 2 weeks in Balb/c mice. Fibroblasts harvested from the skin and subcutaneous tissue of untreated mice served as a control population of cells. All cells were passaged at least twice and then stimulated with a dose range of LPS. Supernatants were harvested 8 hr following stimulation and TNF was assayed using a standard L929 cell-killing assay. There was a significant TNF response to LPS by wound fibroblasts, evident as early as 4 hr following exposure to LPS and associated with an upregulation of TNF mRNA. Normal dermal fibroblasts did not secrete any measurable amounts of TNF in response to LPS. The results indicate that wound fibroblasts generate a brisk TNF response to stimulation with LPS, in contrast to normal subcutaneous fibroblasts. These data reveal an additional unique property of wound-harvested fibroblasts and suggest a possible contributing mechanism to disordered wound healing in the face of infection or conditions characterized by excessive fibrosis.