A new statistical method for haplotype reconstruction from population data

Current routine genotyping methods typically do not provide haplotype information, which is essential for many analyses of fine-scale molecular-genetics data. Haplotypes can be obtained, at considerable cost, experimentally or (partially) through genotyping of additional family members. Alternatively, a statistical method can be used to infer phase and to reconstruct haplotypes. We present a new statistical method, applicable to genotype data at linked loci from a population sample, that improves substantially on current algorithms; often, error rates are reduced by > 50%, relative to its nearest competitor. Furthermore, our algorithm performs well in absolute terms, suggesting that reconstructing haplotypes experimentally or by genotyping additional family members may be an inefficient use of resources.

Functional heterogeneity and high frequencies of cytomegalovirus-specific CD8(+) T lymphocytes in healthy seropositive donors

Human cytomegalovirus (HCMV) infection is largely asymptomatic in the immunocompetent host, but remains a major cause of morbidity in immunosuppressed individuals. Using the recently described technique of staining antigen-specific CD8(+) T cells with peptide-HLA tetrameric complexes, we have demonstrated high levels of antigen-specific cells specific for HCMV peptides and show that this may exceed 4% of CD8(+) T cells in immunocompetent donors. Moreover, by staining with tetramers in combination with antibodies to cell surface markers and intracellular cytokines, we demonstrate functional heterogeneity of HCMV-specific populations. A substantial proportion of these are effector cytotoxic T lymphocytes, as demonstrated by their ability to lyse peptide-pulsed targets in "fresh" killing assays. These data suggest that the immune response to HCMV is periodically boosted by a low level of HCMV replication and that sustained immunological surveillance contributes to the maintenance of host-pathogen homeostasis. These observations should improve our understanding of the immunobiology of persistent viral infection.

Prognostic significance of magnetic resonance imaging-detected extramural vascular invasion in rectal cancer

BACKGROUND

Extramural vascular invasion (EMVI) is a poor prognostic feature in colorectal cancer. The accuracy of magnetic resonance imaging (MRI) in detecting EMVI and predicting relapse-free survival (RFS) was compared retrospectively with the histological reference standard.

METHODS

Preoperative magnetic resonance images from patients diagnosed with rectal and sigmoid cancer were reviewed and an MRI-EMVI score (range 0 to 4) was assigned. Comparison was made with histology and clinical outcome.

RESULTS

Some 142 patients with a median follow-up of 3.3 (range 0.9-5.7) years were reviewed. Histological EMVI was reported in a quarter of patients. The sensitivity and specificity of MRI detection of EMVI in 94 patients undergoing primary surgery were 62 and 88 per cent respectively. On univariable analysis, RFS at 3 years was 35 per cent for patients with an MRI-EMVI score of 3-4, compared with 74 per cent for those with a score of 0-2 (P < 0.001), similar to values in patients with positive and negative histological EMVI status respectively (34 versus 73.7 per cent; P < 0.001).

CONCLUSION

High MRI-EMVI scores may help in predicting disease relapse.

DNA from buccal swabs recruited by mail: evaluation of storage effects on long-term stability and suitability for multiplex polymerase chain reaction genotyping

We provide details of an inexpensive and rapid method for extraction of DNA from buccal swabs (including samples received through the mail) and from a range of other tissue samples. The procedure we have developed provides amounts of DNA adequate for several thousand polymerase chain reactions (PCRs), and we have validated its potential for long-term storage. Samples stored for > 4 years are of comparable concentration and provide as robust PCR templates as those tested immediately after extraction. The availability of this technology is of considerable significance in planning DNA banks from population collections and cohorts.

Effect of ischemia on calcium-dependent fluorescence transients in rabbit hearts containing indo 1. Correlation with monophasic action potentials and contraction

The effects of acute global ischemia on cytosolic calcium transients were studied in perfused rabbit hearts loaded with the fluorescent calcium indicator indo 1. Indo 1-loaded hearts were illuminated at 360 nm, and fluorescence was recorded simultaneously at 400 and 550 nm from the epicardial surface of the left ventricle. The F400/F550 ratio was calculated by an analog circuit, which allowed cancellation of optical motion artifact. Resulting calcium transients demonstrated a rapid upstroke and slow decay similar to those recorded in isolated ventricular myocytes. Global ischemia rapidly suppressed contraction, but it produced a concurrent increase in the systolic and diastolic levels of the calcium transients, together with an increase in the duration of the peak. The effects of ischemia were reversed by reperfusion, inhibited by verapamil, and mimicked by perfusion of nonischemic hearts with acidified (CO2-rich) solution. In addition to elevation of the calcium transients, ischemia caused a pattern of intracellular calcium alternans that was discernible after 2-3 minutes. The pattern of alternans was stable at a given epicardial site, but it could be out of phase at different sites. Similar nonuniformities were observed in contraction strength and in the duration of monophasic action potentials recorded immediately adjacent to the fiber-optic probe. Abnormalities in intracellular calcium may be a causal factor in the loss of electrical and mechanical synchrony in the acutely ischemic heart.

Severe aortic stenosis with impaired left ventricular function and clinical heart failure: results of valve replacement

Nineteen patients, aged 58-80 years, with severe isolated aortic valve stenosis, severely reduced ejection fraction and clinical heart failure underwent aortic valve replacement between January 1970 and April 1977. Ten had concomitant coronary artery disease (all underwent additional coronary bypass surgery), 17 had angina pectoris and four had syncope. Aortic valve area index was 0.32 +/- 0.03 cm2/m2 (mean +/- SEM); left ventricular (LV) end-diastolic volume index was 117 +/- 9 ml/m2 and LV ejection fraction was 0.37 +/- 0.02. There were four operative deaths and one late death. The follow-up time ranged from six to 74 months (38 +/- 6 months). Actuarially determined three-year survival is 74 +/- 10%; the expected five-year survival is the same. One patient had a serious cerebrovascular accident. Of the remaining survivors, seven were initially Functional Class IV and six Class III; currently, six are Class I and seven Class II (New York Heart Association classifications). The cardiothoracic ratio has decreased from 0.54 +/- 0.03 to 0.49 +/- 0.03. Repeat hemodynamic evaluation has been performed in 10 patients, 22 +/- 6 months after surgery. In these 10 patients, the aortic valve gradient decreased from 55 +/- 7 11 +/- 1.3 mm Hg; LV end-diastolic pressure from 22 +/- 2.4 to 9 +/- 1.9 mm Hg; LV end-diastolic volume index from 119 +/- 16 ml/m2 to 107 +/- 11 ml/m2. LV ejection fraction has increased dramatically from 0.34 +/- 0.03 to 0.63 +/- 0.05 and mean velocity of circumferential fiber shortening from 0.57 +/- 0.08 to 1.3 +/- 0.18 circ/sec. The encouraging long-term survival, improved functional class and the marked improvement in left ventricular function that occurred in our patients indicate that all patients with severe aortic stenosis in clinical heart failure should be offered aortic valve replacement.

Treatment for glaucoma: adherence by the elderly

OBJECTIVES

The purpose of this study was to determine the extent of nonadherence to treatment for glaucoma among elderly patients.

METHODS

This was a retrospective cohort study of 2440 patients older than age 65 who were enrolled in the New Jersey Medicaid Program and who were newly initiated on a topical agent for the treatment of glaucoma. Two patient-specific measures of nonadherence were employed: (1) no filled prescription for any glaucoma medication over a 12-month period after the initiation of therapy and (2) number of days without therapy for glaucoma during this 12-month period.

RESULTS

By the first measure, 569 patients (23%) were found to be nonadherent. The mean number of days without therapy during the study year was 112. Factors associated with nonadherence included the use of glaucoma medication requiring more than 2 administrations per day and the presence of multiple other medications in the patient's drug regimen. Patients started on multiple glaucoma medication were more adherent than those started on a single agent. Age and sex were not found to be predictors of nonadherence.

CONCLUSIONS

Substantial nonadherence was found to be common in this population. More attention to the issue of nonadherence could result in important benefits in the preservation of sight.

Cytomegalovirus-seropositivity has a profound influence on the magnitude of major lymphoid subsets within healthy individuals

Cytomegalovirus (CMV) infects most individuals and elicits a strong CMV-specific immune response. We have studied the influence of CMV-seropositivity on the size of lymphoid subsets in healthy donors and demonstrate that the virus substantially modulates the peripheral lymphoid pool. CD8(+) T cell numbers are increased in all CMV-seropositive individuals because of a striking 60% increment in the CD8(+) T cell memory pool. The CD45RA(+) resting memory pool is doubled after CMV infection and increases further with age. The magnitude of the naïve CD8(+) T cell pool is dramatically reduced in CMV-seropositive individuals at all ages, and this accelerates the physiological decline by approximately 40 years. The number of CD4(+) effector memory T cells is increased in CMV-seropositive individuals and is differentially accommodated by a reduction in the number of naïve and central memory CD4(+) T cells in young and elderly donors respectively. CMV-seropositivity also increases the total number of B cells in older donors and suppresses the number of CD5(+) B cells. These data reveal that CMV has a profound influence on the immune system of all healthy individuals and add to growing concern regarding the clinical and immunomodulatory significance of CMV infection in healthy donors.

Health consequences of religious and philosophical exemptions from immunization laws: individual and societal risk of measles

CONTEXT

All US states require proof of immunization for school entry. Exemptions are generally offered for medical, religious, or philosophical reasons, but the health consequences of claiming such exemptions are poorly documented.

OBJECTIVES

To quantify the risk of contracting measles among individuals claiming religious and/or philosophical exemptions from immunization (exemptors) compared with vaccinated persons, and to examine the risk that exemptors pose to the nonexempt population.

DESIGN, SETTING, AND PARTICIPANTS

Population-based, retrospective cohort study of data from 1985 through 1992, collected by the Measles Surveillance System of the Centers for Disease Control and Prevention, as well as from annual state immunization program reports on prevalence of exemptors and vaccination coverage. The study group was restricted to individuals aged 5 to 19 years. To empirically determine and quantify community risk, a mathematical model was developed that examines the spread of measles through communities with varying proportions of exemptors and vaccinated children.

MAIN OUTCOME MEASURES

Relative risk of contracting measles for exemptors vs vaccinated individuals based on cohort study data. Community risk of contracting measles derived from a mathematical model.

RESULTS

On average, exemptors were 35 times more likely to contract measles than were vaccinated persons (95% confidence interval, 34-37). Relative risk varied by age and year. Comparing the incidence among exemptors with that among vaccinated children and adolescents during the years 1985-1992 indicated that the 1989-1991 measles resurgence may have occurred 1 year earlier among exemptors. Mapping of exemptors by county in California indicated that exempt populations tended to be clustered in certain geographic regions. Depending on assumptions of the model about the degree of mixing between exemptors and nonexemptors, an increase or decrease in the number of exemptors would affect the incidence of measles in nonexempt populations. If the number of exemptors doubled, the incidence of measles infection in nonexempt individuals would increase by 5.5%, 18.6%, and 30.8%, respectively, for intergroup mixing ratios of 20%, 40%, and 60%.

CONCLUSIONS

These data suggest the need for systematic review of vaccine-preventable incidents to examine the effect of exemptors, increased surveillance of the number of exemptors and cases among them, and research to determine the reasons why individuals claim exemptions.

Modified Gallie technique versus transarticular screw fixation in C1-C2 fusion

The effectiveness of a modified Gallie technique versus Magerl and Seeman transarticular screw fixation was compared in the management of 27 patients with symptomatic atlantoaxial instability. Twelve patients were treated using a modified Gallie technique and postoperative halo vest immobilization. Atlantoaxial arthrodesis occurred in seven (58%) patients, stable fibrous union occurred in one patient, and pseudarthrosis with recurrent instability developed in four (33%) patients. Average followup was 6.9 years. All 15 patients treated using Magerl and Seeman transarticular screw fixation and postoperative soft collar immobilization had atlantoaxial arthrodesis develop. Average duration of followup was 4 years. One patient sustained vertebral artery injury during preparation for screw placement. Magerl and Seeman transarticular screw fixation provides stability and more reliably produces atlantoaxial arthrodesis than the Gallie technique provides in patients with atlantoaxial instability without the need for rigid postoperative bracing. Potential for vertebral artery exists despite apparent accurate screw placement. To ensure that safe transarticular screw placement is possible, preoperative fine cut axial computed tomography with reconstructions is required to assess vertebral artery position and C2 isthmus anatomy. A proportion of patients have anatomy unsuitable for screw placement. Traditional wiring techniques are indicated in these patients.

Time trends in autism and in MMR immunization coverage in California

CONTEXT

Considerable concern has been generated in the lay and medical communities by a theory that increased measles-mumps-rubella (MMR) immunization among young children may be the cause of an apparent marked increase in autism occurrence.

OBJECTIVE

To determine if a correlation exists in secular trends of MMR immunization coverage among young children and autism occurrence.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective analyses of MMR immunization coverage rates among children born in 1980-1994 who were enrolled in California kindergartens (survey samples of 600-1900 children each year) and whose school immunization records were reviewed to retrospectively determine the age at which they first received MMR immunization; and of autism caseloads among children born in these years who were diagnosed with autism and were enrolled in the California Department of Developmental Services regional service center system.

MAIN OUTCOME MEASURES

Measles-mumps-rubella immunization coverage rates as of ages 17 months and 24 months and numbers of Department of Developmental Services system enrollees diagnosed with autism, grouped by year of birth.

RESULTS

Essentially no correlation was observed between the secular trend of early childhood MMR immunization rates in California and the secular trend in numbers of children with autism enrolled in California's regional service center system. For the 1980-1994 birth cohorts, a marked, sustained increase in autism case numbers was noted, from 44 cases per 100 000 live births in the 1980 cohort to 208 cases per 100 000 live births in the 1994 cohort (a 373% relative increase), but changes in early childhood MMR immunization coverage over the same time period were much smaller and of shorter duration. Immunization coverage by the age of 24 months increased from 72% to 82%, a relative increase of only 14%, over the same time period.

CONCLUSIONS

These data do not suggest an association between MMR immunization among young children and an increase in autism occurrence.

Bovine pulmonary surfactant: chemical composition and physical properties

Bovine pulmonary surfactant was obtained by endotracheal lavage of lungs from newly slaughtered cows followed by differential centrifugation. Lipid extracts of bovine surfactant contained 3% neutral lipid, mainly as cholesterol and diacylglycerol and 97% phospholipid. Phosphatidylcholine (79%) and phosphatidylglycerol (11%) accounted for most of the phospholipids with smaller amounts of phosphatidylethanolamine, phosphatidylinositol, lyso-bis-phosphatidic acid and sphingomyelin. Fatty acid analysis revealed high levels of palmitate in phosphatidylcholine and to a lesser extent phosphatidylglycerol, but not in the other diacylphospholipids. Phosphatidylcholine was 53% disaturated and phosphatidylglycerol was 23% disaturated. Monoenoic species accounted for the major proportion of the remaining lipid. The protein content was 10% as estimated by the Lowry procedure and 5% when determined by amino acid analysis. Extraction with chloroform/methanol removed ca. 90% of the protein but had no effect on the surfactant properties as evaluated by a pulsating bubble technique.

Free triiodothyronine has a distinct circadian rhythm that is delayed but parallels thyrotropin levels

CONTEXT

TSH is known to have a circadian rhythm, but the relationship between this and any rhythm in T(4) and T(3) has not been clearly demonstrated.

OBJECTIVE

With a view to optimizing thyroid hormone replacement therapy, we have used modern assays for free T(4) (FT4) and free T(3) (FT3) to investigate circadian rhythmicity.

SETTING

The study was performed at a university hospital.

DESIGN AND SUBJECTS

This was a cross-sectional study in 33 healthy individuals with 24-h blood sampling (TSH in 33 and FT4 and FT3 in 29 individuals) and cosinor analysis.

RESULTS

Of the individuals, 100% showed a sinusoidal signal in TSH, for FT4 76%, and for FT3 86% (P < 0.05). For FT4 and FT3, the amplitude was low. For TSH the acrophase occurred at a clock time of 0240 h, and for FT3 approximately 90 minutes later at 0404 h. The group cosinor model predicts that TSH hormone levels remain above the mesor between 2020 and 0820 h, and for FT3 from 2200-1000 h. Cross correlation of FT3 with TSH showed that the peak correlation occurred with a delay of 0.5-2.5 h. When time-adjusted profiles of TSH and FT3 were compared, there was a strong correlation between FT3 and TSH levels (rho = 0.80; P < 0.0001). In contrast, cross correlation revealed no temporal relationship between FT4 and TSH.

CONCLUSIONS

FT3 shows a circadian rhythm with a periodicity that lags behind TSH, suggesting that the periodic rhythm of FT3 is due to the proportion of T(3) derived from the thyroid. Optimizing thyroid hormone replacement may need to take these rhythms into account.

An epidemiological study to establish the prevalence of urinary symptoms and felt need in the community: the Leicestershire MRC Incontinence Study. Leicestershire MRC Incontinence Study Team

BACKGROUND

The aim of the study was to establish the prevalence of urinary symptoms and felt need in adults. This paper discusses problems with setting thresholds to distinguish cases from non-cases in this field of research. Few studies have provided detailed age- and sex-specific prevalence estimates for felt need in relation to urinary symptoms.

METHODS

A cross-sectional postal survey was carried out of 15,904 community-dwelling adults aged 40 years or more registered with general practitioners in Leicestershire. Subjects were selected randomly by household from the Leicestershire Health Authority Register. The postal questionnaire consisted of questions on general health, urinary and bowel symptoms, quality of life, service use and demographic characteristics.

RESULTS

Thirty-four per cent of the sample reported clinically significant symptoms. The prevalence and severity of symptoms increased with age. However, only 2 per cent of the sample reported symptoms that were clinically significant, bothersome and socially disabling.

CONCLUSION

Urinary symptoms are very common in adults over 40 years of age living in the community. However, symptom-based estimates probably overestimate the level of need for health care in the community. It may be more effective and efficient to target services, in the first instance, on those people who report clinically significant symptoms that are bothersome or socially disabling. A consensus on thresholds and definitions of urinary symptoms is required to standardize clinical and research work and to target services more appropriately.

Design of biomimetic habitats for tissue engineering with P-15, a synthetic peptide analogue of collagen

In tissues, collagen forms the scaffold for cell attachment and migration, and it modulates cell differentiation and morphogenesis by mediating the flux of chemical and mechanical stimuli. We are constructing biomimetic environments by immobilizing a collagen-derived high-affinity cell-binding peptide P-15 in three-dimensional (3-D) templates. The cell-binding peptide can be expected to transduce mechanical forces. In their physiological environment, periodontal ligament fibroblasts (PDLF) are subject to significant mechanical forces. We have examined the behavior of human PDLF in culture on particulate bovine anorganic bone mineral (ABM) coated with P-15 (ABM-P-15). Greater numbers of cells associated with ABM-P-15 compared to ABM alone. Higher levels of incorporation of radiolabeled precursors in DNA and protein were consistent with the presence of larger numbers of cells on ABM-P-15 compared to ABM cultures. Scanning electron microscopic examination showed that cultures on ABM-P-15 generated highly oriented 3-D colonies of elongated cells and formed copious amounts of fibrous as well as membranous matrix reminiscent of ligamentous structures. PDLF cultured on ABM formed sparse monolayers with little order and a meager matrix. Alizarin Red stained the matrix of particle associated cells and inter-particle cellular bridges in P-15-associated cultures, indicating mineralization. 3-D colony formation and ordering of cells along with increased mineralization suggests that the coupling of cells to the ABM matrix through P-15 may provide a biomimetic environment permissive for cell differentiation and morphogenesis. Our studies suggest that ABM-P-15 templates may be effective as endosseous grafts, and, when seeded with PDLF, these matrices may serve as tissue engineered substitutes for autologous bone grafts.

Antigens of human trophoblasts: a working hypothesis for their role in normal and abnormal pregnancies

This report describes the preparation and characterization of antisera to human trophoblast membranes. Rabbit antisera were raised to trophoblast microvilli prepared by differential ultracentrifugation. Antibodies to serum proteins were removed by solid-phase immunoabsorption with normal human serum, and indirect immunofluorescence experiments with cryostat sections of human placentas showed that the absorbed anti-trophoblast sera reacted with trophoblasts as well as with stromal cells and endothelium of chorionic villi. The antisera also produced membrane fluorescence when studied on viable lymphocytes and certain human cell lines. These anti-trophoblast sera were also lymphocytotoxic, and this reaction was abolished by prior absorption of the antisera with leukocytes. The leukocyte-absorbed anti-trophoblast sera retained their ability to react with trophoblasts and certain human cell lines, but no longer reacted with lymphocytes or placental stromal cells and endothelium. Two categories of trophoblast membrane antigens are thus defined: one present on trophoblasts and certain human cells lines (tentatively designated TA(1)), and the other on trophoblasts and lymphocytes, villous fibroblasts, and endothelium (tentatively designated TA(2)). A working hypothesis is proposed stating that normal pregnancy involves the generation of anti-TA(2) subsequent to blastocyst implantation and entrance of trophoblasts into the maternal circulation. This involves a mechanism similar to allogeneic cell stimulation and results in antibodies that block either the recognition or cytotoxicity of TA(1). Failure to mount this response allows TA(1) recognition and trophoblast immunopathology. Experimental and clinical studies in support of this working hypothesis, particularly involving abortion and toxemia, are cited from published reports.

L-Lactic acid: a mosquito attractant isolated from humans

L-Lactic acid was the major component in material isolated from humans that was active as an attractant for female yellow fever mosquitoes, Aedes aegypti (L.). The L(+)-isomer was several times as attractive as the D-isomer. Good correlation was found between the attractiveness of an individual to mosquitoes and the quantity of lactic acid present in an acetone washing of his hand.

Dermatofibrosarcoma protuberans: a clinicopathological and immunohistochemical study with a review of the literature

Forty-one cases of dermatofibrosarcoma protuberans are presented. The clinical features and histopathological appearances are described. Immunohistochemical staining of thirteen cases with antisera to lysozyme, alpha 1-antichymotrypsin and S-100 protein has provided no evidence to support either a histiocytic or neuroectodermal origin for these tumours. In reviewing the literature, the histogenetic origin, differential diagnosis and malignant potential of dermatofibrosarcoma protuberans are discussed.

Evidence based general practice: a retrospective study of interventions in one training practice

OBJECTIVES

To estimate the proportion of interventions in general practice that are based on evidence from clinical trials and to assess the appropriateness of such an evaluation.

DESIGN

Retrospective review of case notes.

SETTING

One suburban training general practice.

SUBJECTS

122 consecutive doctor-patient consultations over two days.

MAIN OUTCOME MEASURES

Proportions of interventions based on randomised controlled trials (from literature search with Medline, pharmaceutical databases, and standard textbooks), on convincing non-experimental evidence, and without substantial evidence.

RESULTS

21 of the 122 consultations recorded were excluded due to insufficient data; 31 of the interventions were based on randomised controlled trial evidence and 51 based on convincing non-experimental evidence. Hence 82/101 (81%) of interventions were based on evidence meeting our criteria.

CONCLUSIONS

Most interventions within general practice are based on evidence from clinical trials, but the methods used in such trials may not be the most appropriate to apply to this setting.

Persistency of response to omalizumab therapy in severe allergic (IgE-mediated) asthma

BACKGROUND

The physician's global evaluation of treatment effectiveness (GETE) at 16 weeks has been shown to be the most effective assessment of response to omalizumab (XOLAIR®). This randomized, open-label, parallel-group study evaluated the persistency of treatment responder classification in patients receiving omalizumab added to optimized asthma therapy (OAT).

METHODS

Patients (12-75 years, n = 400) with severe allergic asthma, uncontrolled despite Global Initiative for Asthma 2004 Step 4 therapy, received OAT and omalizumab (n = 272) or OAT (n = 128) for 32 weeks. Response or nonresponse was evaluated at Weeks 16 and 32. Response was defined as an investigator's (physician's) GETE rating of excellent or good; nonresponse was defined as a rating of moderate, poor or worsening.

RESULTS

Three hundred and forty-nine patients had GETE ratings available at Weeks 16 and 32 (omalizumab n = 258, OAT n = 91). Omalizumab responders of about 171/187 (91.4%)and 44/71 (62.0%) omalizumab nonresponders at Week 16 persisted as responders or nonresponders at Week 32. The investigator's GETE at Week 16 predicted persistency of response or nonresponse to omalizumab at Week 32 for 83.3% (215/258) of patients. OAT patients showed a lower persistency of response (18/28 [64.3%]) and a higher persistency of nonresponse (57/63 [90.5%]) than omalizumab patients. Excellent and good GETE ratings in omalizumab-treated patients were reflected by improvements in exacerbation rates (P < 0.001), severe exacerbation rates (P = 0.023), hospitalizations (P = 0.003), total emergency visits (P = 0.026) and Asthma Control Questionnaire overall score (P < 0.001).

CONCLUSION

Response to omalizumab, as assessed by a physician's GETE at 16 weeks, is an effective predictor of continuing persistent response to omalizumab for the majority of patients.

IL-6 acts on endothelial cells to preferentially increase their adherence for lymphocytes

Using a quantitative monolayer adhesion assay, the current report shows that treatment of human umbilical vein endothelial cells (HUVEC) with IL-6 increases their adhesiveness for blood lymphocytes, particularly CD4+ cells, but not for polymorphonuclear cells and monocytes. This effect, which was most pronounced when using low concentrations of the cytokine (0.1-1.0 U/ml) and a short incubation period (4h), was also apparent with microvascular endothelial cells and a hybrid endothelial cell line. Skin lesions from patients with mycosis fungoides contain high levels of IL-6, and blood lymphocytes from patients with this disorder also exhibited an enhanced adhesion to IL-6-treated HUVEC. The cytokine enhanced intercellular adhesion molecule-1 (ICAM-1) expression and induced the expression of vascular cell adhesion molecule-1 (VCAM-1) and E-selectin on endothelial cells. Antibody blocking studies demonstrated that the vascular adhesion molecules ICAM-1, VCAM-1 and E-selectin and the leucocyte integrin LFA-1 all contributed to lymphocyte binding to endothelium activated by IL-6. It is proposed that IL-6 may be involved in the recruitment of lymphocytes into non-lymphoid tissue.

Preoperative computed tomography staging of nonmetastatic colon cancer predicts outcome: implications for clinical trials

Colon cancer patients routinely undergo preoperative computed tomography (CT) scanning, but local staging is thought to be inaccurate. We aimed to determine if clinical outcome could be predicted from radiological features of the primary tumour. Consecutive patients at one hospital undergoing primary resection for colon cancer during 2000-2004 were included. Patients with visible metastases were excluded. Preoperative CT scans were reviewed independently by two radiologists blinded to histological stage and outcome. Images of the primary tumour were evaluated according to conventional TNM criteria and patients were stratified into 'good' or 'poor' prognosis groups. Comparison was made between prognostic group and actual clinical outcome. Hundred and twenty-six preoperative CT scans were reviewed. T-stage and nodal status was correctly predicted in only 60 and 62%, respectively. However, inter-observer agreement for prognostic group was 79% (kappa=0.59) and 3-year relapse-free survival was 71 and 43% for the CT-predicted 'good' and 'poor' groups, respectively (P<0.0066). This compared favourably with 75 vs 43% for histology-predicted prognostic groups. Computed tomography is a robust method for stratifying patients preoperatively, with similar accuracy to histopathology for predicting outcome. Recognition of poor prognosis tumours preoperatively may permit investigation into the future use of neo-adjuvant therapy in colon cancer.

Cytosolic calcium transients from the beating mammalian heart

To elucidate the role of cytosolic calcium, [Ca2+]i, in the physiology of the normal and ischemic heart, we have developed a method for recording [Ca2+]i transients from the epicardial surface of the rabbit ventricle after arterial perfusion with the cell-permeant cytosolic calcium indicator indo-1 AM. Hearts were illuminated at 360 nm, and fluorescence was recorded simultaneously at 400 and 550 nm. The F400/F550 fluorescence ratio was calculated by an analog circuit that allowed cancelation of small movement artifacts that were present at single wavelengths. Clear [Ca2+]i transients were present in the F400/F550 signal and were remarkable for their slow decay. Slow decay of the transients was not due to buffering of [Ca2+]i by indo-1, since there was no associated impairment of contraction or relaxation. The peak amplitude of the [Ca2+]i transients was increased by ouabain, adrenaline, postextrasystolic potentiation, and acetylcholine. The extent to which the transients decayed diminished with shortening of the interbeat interval, but decay of the transients could be further diminished by acetylcholine or caffeine. A major advantage of the intact heart over isolated myocytes is the ability to measure changes in [Ca2+]i during ischemia. Ischemia produced a marked increase in both peak systolic and end-diastolic [Ca2+]i, which was most rapid during the first 30 sec, and approached a plateau value after 90 sec. This increase in [Ca2+]i was associated with a characteristic broadening of the peak of the transient. The increase in [Ca2+]i during ischemia is consistent with a proposed causative role of [Ca2+]i in mediating early electrophysiological abnormalities.