Zoonotic Transmission of Campylobacter jejuni to Caretakers From Sick Pen Calves Carrying a Mixed Population of Strains With and Without Guillain Barré Syndrome-Associated Lipooligosaccharide Loci

Campylobacter jejuni causes foodborne gastroenteritis and may trigger acute autoimmune sequelae including Guillain Barré Syndrome. Onset of neuromuscular paralysis is associated with exposure to C. jejuni lipooligosaccharide (LOS) classes A, B, C, D, and E that mimic and evoke antibodies against gangliosides on myelin and axons of peripheral nerves. Family members managing a Michigan dairy operation reported recurring C. jejuni gastroenteritis. Because dairy cattle are known to shed C. jejuni, we hypothesized that calves in the sick pen were the source of human infections. Fecal samples obtained from twenty-five calves, one dog, and one asymptomatic family member were cultured for Campylobacter. C. jejuni isolates were obtained from thirteen calves and the family member: C. coli from two calves, and C. hyointestinalis from two calves. Some calves had diarrhea; most were clinically normal. Typing of lipooligosaccharide biosynthetic loci showed that eight calf C. jejuni isolates fell into classes A, B, and C. Two calf isolates and the human isolate possessed LOS class E, associated mainly with enteric disease and rarely with Guillain Barré Syndrome. Multi-locus sequence typing, porA and flaA typing, and whole genome comparisons of the thirteen C. jejuni isolates indicated that the three LOS class E strains that included the human isolate were closely related, indicating zoonotic transmission. Whole-genome comparisons revealed that isolates differed in virulence gene content, particularly in loci encoding biosynthesis of surface structures. Family members experienced diarrheal illness repeatedly over 2 years, yet none experienced GBS despite exposure to calves carrying invasive C. jejuni with LOS known to elicit antiganglioside autoantibodies.

Th1/Th17-mediated Immunity and Protection from Peripheral Neuropathy in Wildtype and IL10-/- BALB/c Mice Infected with a Guillain-Barré Syndrome-associated Campylobacter jejuni Strain

Campylobacter jejuni is an important cause of bacterial gastroenteritis worldwide and is linked to Guillain-Barré syndrome (GBS), a debilitating postinfectious polyneuropathy. The immunopathogenesis of GBS involves the generation of antibodies that are cross reactive to C. jejuni lipooligosaccharide and structurally similar peripheral nerve gangliosides. Both the C. jejuni infecting strain and host factors contribute to GBS development. GBS pathogenesis is associated with Th2-mediated responses in patients. Moreover, induction of IgG1 antiganglioside antibodies in association with colonic Th2-mediated immune responses has been reported in C. jejuni-infected C57BL/6 IL10-/- mice at 4 to 6 wk after infection. We hypothesized that, due to their Th2 immunologic bias, BALB/c mice would develop autoantibodies and signs of peripheral neuropathy after infection with a GBS patient-derived strain of C. jejuni (strain 260.94). WT and IL10-/- BALB/c mice were orally inoculated with C. jejuni 260.94, phenotyped weekly for neurologic deficits, and euthanized after 5 wk. Immune responses were assessed as C. jejuni-specific and antiganglioside antibodies in plasma and cytokine production and histologic lesions in the proximal colon. Peripheral nerve lesions were assessed in dorsal root ganglia and their afferent nerve fibers by scoring immunohistochemically labeled macrophages through morphometry. C. jejuni 260.94 stably colonized both WT and IL10-/- mice and induced systemic Th1/Th17-mediated immune responses with significant increases in C. jejuni-specific IgG2a, IgG2b, and IgG3 plasma antibodies. However, C. jejuni 260.94 did not induce IgG1 antiganglioside antibodies, colitis, or neurologic deficits or peripheral nerve lesions in WT or IL10-/- mice. Both WT and IL10-/- BALB/c mice showed relative protection from development of Th2-mediated immunity and antiganglioside antibodies as compared with C57BL/6 IL10-/- mice. Therefore, BALB/c mice infected with C. jejuni 260.94 are not an effective disease model but provide the opportunity to study the role of immune mechanisms and host genetic background in the susceptibility to post infectious GBS.

Comparison of Effects of Trichuris muris and Spontaneous Colitis on the Proximal Colon Microbiota in C3H/HeJ and C3Bir IL10-/- Mice

The nematode Trichuris muris has been shown to interact with specific enteric bacteria, but its effects on the composition of its host's microbial community are not fully understood. We hypothesized that Trichuris muris-infected mice would have altered colon microbiota as compared with uninfected mice. Colon histopathology and microbial community structure and composition were examined in mouse models of colitis (C3BirTLR4^-/- IL10^-/- and C3H/HeJ TLR4^-/- IL10^+/+ mice) with and without T. muris infection, in uninfected C3BirIL10^-/- mice with and without spontaneous colitis, and in normal C3H/ HeJ mice. T. muris-infected mice developed colon lesions that were more severe than those seen in IL10-deficient mice. Ap- proximately 80% of infected IL10^-/- mice had colon neutrophilic exudates, and some had extraintestinal worms and bacteria. The composition and structure of proximal colon microbiota were assessed by using terminal restriction fragment length polymorphism analysis targeting the bacterial 16S rRNA gene. Colon microbiota in C3BirIL10^-/- and C3H/HeJ mice differed both qualitatively and quantitatively. Trichuris infection significantly altered the relative abundance of individual operational taxonomic units [OTU] but not the composition (presence or absence of OTU) of colon microbiota in the 2 mouse genotypes. When C3BirIL10^-/- and C3H/HeJ mouse OTU were considered separately, Trichuris was found to affect the microbiota of C3BirIL10^-/- mice but not of C3H/HeJ mice. Even though 34 of the 75 (45%) C3BirIL10^-/- mice had spontaneous colitis, neither qualitative nor quantitative differences were detected in microbiota between colitic or noncolitic C3BirIL10^-/- mice or noncolitic C3H/HeJ mice. Therefore, Trichuris-infected mice developed distinct microbial communities that were influenced by host background genes; these alterations cannot be attributed solely to colonic inflammation.

Experimental Evolution of Campylobacter jejuni Leads to Loss of Motility, rpoN (σ54) Deletion and Genome Reduction

Evolution experiments in the laboratory have focused heavily on model organisms, often to the exclusion of clinically relevant pathogens. The foodborne bacterial pathogen Campylobacter jejuni belongs to a genus whose genomes are small compared to those of its closest genomic relative, the free-living genus Sulfurospirillum, suggesting genome reduction during the course of evolution to host association. In an in vitro experiment, C. jejuni serially passaged in rich medium in the laboratory exhibited loss of flagellar motility-an essential function for host colonization. At early time points the motility defect was often reversible, but after 35 days of serial culture, motility was irreversibly lost in most cells in 5 independently evolved populations. Population re-sequencing revealed disruptive mutations to genes in the flagellar transcriptional cascade, rpoN (σ54)-therefore disrupting the expression of the genes σ54 regulates-coupled with deletion of rpoN in all evolved lines. Additional mutations were detected in virulence-related loci. In separate in vivo experiments, we demonstrate that a phase variable (reversible) motility mutant carrying an adenine deletion within a homopolymeric tract resulting in truncation of the flagellar biosynthesis gene fliR was deficient for colonization in a C57BL/6 IL-10-/- mouse disease model. Re-insertion of an adenine residue partially restored motility and ability to colonize mice. Thus, a pathogenic C. jejuni strain was rapidly attenuated by experimental laboratory evolution and demonstrated genomic instability during this evolutionary process. The changes observed suggest C. jejuni is able to evolve in a novel environment through genome reduction as well as transition, transversion, and slip-strand mutations.

An antibiotic depleted microbiome drives severe Campylobacter jejuni-mediated Type 1/17 colitis, Type 2 autoimmunity and neurologic sequelae in a mouse model

The peripheral neuropathy Guillain-Barré Syndrome can follow Campylobacter jejuni infection when outer core lipooligosaccharides induce production of neurotoxic anti-ganglioside antibodies. We hypothesized that gut microbiota depletion with an antibiotic would increase C. jejuni colonization, severity of gastroenteritis, and GBS. Microbiota depletion increased C. jejuni colonization, invasion, and colitis with Type 1/17 T cells in gut lamina propria. It also stimulated Type 1/17 anti-C. jejuni and -antiganglioside-antibodies, Type 2 anti-C. jejuni and -antiganglioside antibodies, and neurologic phenotypes. Results indicate that both C. jejuni strain and gut microbiota affect development of inflammation and GBS and suggest that probiotics following C. jejuni infection may ameliorate inflammation and autoimmune disease.

Can the use of an inclinometer improve the positioning of the acetabular component in total hip arthroplasty?

Aims

Accurate placement of the acetabular component is essential in total hip arthroplasty (THA). The purpose of this study was to determine if the ability to achieve inclination of the acetabular component within the 'safe-zone' of 30° to 50° could be improved with the use of an inclinometer.

Patients and Methods

We reviewed 167 primary THAs performed by a single surgeon over a period of 14 months. Procedures were performed at two institutions: an inpatient hospital, where an inclinometer was used (inclinometer group); and an ambulatory centre, where an inclinometer was not used as it could not be adequately sterilized (control group). We excluded 47 patients with a body mass index (BMI) of > 40 kg/m², age of > 68 years, or a surgical indication other than osteoarthritis whose treatment could not be undertaken in the ambulatory centre. There were thus 120 patients in the study, 68 in the inclinometer group and 52 in the control group. The inclination angles of the acetabular component were measured from de-identified plain radiographs by two blinded investigators who were not involved in the surgery. The effect of the use of the inclinometer on the inclination angle was determined using multivariate regression analysis.

Results

The mean inclination angle for the THAs in the inclinometer group was 42.9° (95% confidence interval (CI) 41.7° to 44.0°; range 29.0° to 63.8°) and 46.5° (95% CI 45.2° to 47.7°; range 32.8° to 63.2°) in the control group (p < 0.001). Regression analysis identified a 9.1% difference in inclination due to the use of an inclinometer (p < 0.001), and THAs performed without the inclinometer were three times more likely to result in inclination angles of > 50° (odds ratio (OR) 2.8, p = 0.036). The correlation coefficient for the interobserver reliability of the measurement of the two investigators was 0.95 (95% CI 0.93 to 0.97).

Conclusion

The use of a simple inclinometer resulted in a significant reduction in the number of outliers compared with a freehand technique. Cite this article: Bone Joint J 2018;100-B:862-6.

The Electrocardiogram in General Practice: Its Use and Its Interpretation

General practitioners in one health district were surveyed by postal questionnaire (including 15 sample electrocardiogram tracings) to assess their usage and competence in interpretation of the electrocardiogram. A response rate of 60% was achieved, of whom 40% said they used the electrocardiogram at least monthly and 43% used it 'always' or 'usually' in patients with suspected myocardial infarction at home. Overall competence in recognizing a variety of abnormalities was felt to be good. Recent qualification, the possession of a higher qualification (MRCP/MRCGP) and frequency of usage were associated with better performance. Even so, unequivocal acute myocardial infarction was misdiagnosed by 20% of respondents. These findings have implications for the provision of electrocardiographic services in primary care and the management of patients in the home with suspected myocardial infarction, particularly with the advent of thrombolytic therapy.

First Record of Leucocytozoon (Haemosporida: Leucocytozoidae) in Amazonia: Evidence for Rarity in Neotropical Lowlands or Lack of Sampling for This Parasite Genus?

Birds harbor an astonishing diversity of haemosporidian parasites belonging to the genera Haemoproteus, Leucocytozoon, and Plasmodium. Currently there are more than 250 morphologically described avian haemosporidian species and 2,828 unique lineages found in virtually all avian clades and zoogeographic regions, except for Antarctica. Our report is based on PCR and microscopic screening of 1,302 individual avian samples from Brazil to detect the underrepresented genus Leucocytozoon. This survey primarily focuses on passerine birds collected from Amazonia, the Atlantic Rain Forest, and Pantanal. We also summarize studies conducted in Brazil that report haemosporidian prevalence using both microscopy and molecular tools and present for the first time a record of Leucocytozoon infecting an avian host population in Amazonia. Based on our findings, we suggest that high average temperatures may be constraining both the distribution and diversity of Leucocytozoon in lowland tropical South America.

Transplanted human fecal microbiota enhanced Guillain Barré syndrome autoantibody responses after Campylobacter jejuni infection in C57BL/6 mice

BACKGROUND

Campylobacter jejuni is the leading antecedent infection to the autoimmune neuropathy Guillain-Barré syndrome (GBS), which is accompanied by an autoimmune anti-ganglioside antibody attack on peripheral nerves. Previously, we showed that contrasting immune responses mediate C. jejuni induced colitis and autoimmunity in interleukin-10 (IL-10)-deficient mice, dependent upon the infecting strain. Strains from colitis patients elicited T helper 1 (T_H1)-dependent inflammatory responses while strains from GBS patients elicited T_H2-dependent autoantibody production. Both syndromes were exacerbated by antibiotic depletion of the microbiota, but other factors controlling susceptibility to GBS are unknown.

METHODS

Using 16S rRNA gene high-throughput sequencing, we examined whether structure of the gut microbial community alters host (1) gastrointestinal inflammation or (2) anti-ganglioside antibody responses after infection with C. jejuni strains from colitis or GBS patients. We compared these responses in C57BL/6 mice with either (1) stable human gut microbiota (^Humicrobiota) transplants or (2) conventional mouse microbiota (^Convmicrobiota).

RESULTS

Inoculating germ-free C57BL/6 wild-type (WT) mice with a mixed human fecal slurry provided a murine model that stably passed its microbiota over >20 generations. Mice were housed in specific pathogen-free (SPF) facilities, while extra precautions of having caretakers wear sterile garb along with limited access ensured that no mouse pathogens were acquired. ^Humicrobiota conferred many changes upon the WT model in contrast to previous results, which showed only colonization with no disease after C. jejuni challenge. When compared to ^Convmicrobiota mice for susceptibility to C. jejuni enteric or GBS patient strains, infected ^Humicrobiota mice had (1) 10-100 fold increases in C. jejuni colonization of both strains, (2) pathologic change in draining lymph nodes but only mild changes in colon or cecal lamina propria, (3) significantly lower Th1/Th17-dependent anti-C. jejuni responses, (4) significantly higher IL-4 responses at 5 but not 7 weeks post infection (PI), (5) significantly higher Th2-dependent anti-C. jejuni responses, and (6) significantly elevated anti-ganglioside autoantibodies after C. jejuni infection. These responses in ^Humicrobiota mice were correlated with a dominant Bacteroidetes and Firmicutes microbiota.

CONCLUSIONS

These data demonstrate that ^Humicrobiota altered host-pathogen interactions in infected mice, increasing colonization and Th-2 and autoimmune responses in a C. jejuni strain-dependent manner. Thus, microbiota composition is another factor controlling susceptibility to GBS.

Healthy obesity and risk of accelerated functional decline and disability

BACKGROUND/OBJECTIVES

Some obese adults have a normal metabolic profile and are considered 'healthy', but whether they experience faster ageing than healthy normal-weight adults is unknown. We compared decline in physical function, worsening of bodily pain and likelihood of future mobility limitation and disability between these groups.

SUBJECTS/METHODS

This was a population-based observational study using repeated measures over 2 decades (Whitehall II cohort data). Normal-weight (body mass index (BMI) 18.5-24.9 kg m-2), overweight (25.0-29.9 kg m-2) and obese (⩾30.0 kg m-2) adults were considered metabolically healthy if they had 0 or 1 of 5 risk factors (hypertension, low high-density lipoprotein cholesterol, high triacylglycerol, high blood glucose and insulin resistance) in 1991/1994. Decline in physical function and worsening of bodily pain based on change in Short Form Health Survey items using eight repeated measures over 18.8 years (1991/1994-2012/2013) were compared between metabolic-BMI groups using linear mixed models. Odds of mobility limitation based on objective walking speed (slowest tertile) and of disability based on limitations in ⩾1 of 6 basic activities of daily living, each using three repeated measures over 8.3 years (2002/2004-2012/2013), were compared using logistic mixed models.

RESULTS

In multivariable-adjusted mixed models on up to 6635 adults (initial mean age 50 years; 70% male), healthy normal-weight adults experienced a decline in physical function of -3.68 (95% CI=-4.19, -3.16) score units per decade; healthy obese adults showed an additional -3.48 (-4.88, -2.08) units decline. Healthy normal-weight adults experienced a -0.49 (-1.11, 0.12) score unit worsening of bodily pain per decade; healthy obese adults had an additional -2.23 (-3.78, -0.69) units worsening. Healthy obesity versus healthy normal-weight conferred 3.39 (2.29, 5.02) times higher odds of mobility limitation and 3.75 (1.94, 7.24) times higher odds of disability.

CONCLUSIONS

Our results suggest that obesity, even if metabolically healthy, accelerates age-related declines in functional ability and poses a threat to independence in older age.

Guillain Barré Syndrome is induced in Non-Obese Diabetic (NOD) mice following Campylobacter jejuni infection and is exacerbated by antibiotics

Campylobacter jejuni is a leading cause of bacterial gastroenteritis linked to several serious autoimmune sequelae such as the peripheral neuropathies Guillain Barré syndrome (GBS) and Miller Fisher syndrome (MFS). We hypothesized that GBS and MFS can result in NOD wild type (WT) mice or their congenic interleukin (IL)-10 or B7-2 knockouts secondary to C. jejuni infection. Mice were gavaged orally with C. jejuni strains HB93-13 and 260.94 from patients with GBS or CF93-6 from a patient with MFS and assessed for clinical neurological signs and phenotypes, anti-ganglioside antibodies, and cellular infiltrates and lesions in gut and peripheral nerve tissues. Significant increases in autoantibodies against single gangliosides (GM1, GQ1b, GD1a) occurred in infected NOD mice of all genotypes, although the isotypes varied (NOD WT had IgG1, IgG3; NOD B7-2^-/- had IgG3; NOD IL-10^-/- had IgG1, IgG3, IgG2a). Infected NOD WT and NOD IL-10^-/- mice also produced anti-ganglioside antibodies of the IgG1 isotype directed against a mixture of GM1/GQ1b gangliosides. Phenotypic tests showed significant differences between treatment groups of all mouse genotypes. Peripheral nerve lesions with macrophage infiltrates were significantly increased in infected mice of NOD WT and IL-10^-/- genotypes compared to sham-inoculated controls, while lesions with T cell infiltrates were significantly increased in infected mice of the NOD B7-2^-/- genotype compared to sham-inoculated controls. In both infected and sham inoculated NOD IL-10^-/- mice, antibiotic treatment exacerbated neurological signs, lesions and the amount and number of different isotypes of antiganglioside autoantibodies produced. Thus, inducible mouse models of post-C. jejuni GBS are feasible and can be characterized based on evaluation of three factors-onset of GBS clinical signs/phenotypes, anti-ganglioside autoantibodies and nerve lesions. Based on these factors we characterized 1) NOD B-7^-/- mice as an acute inflammatory demyelinating polyneuropathy (AIDP)-like model, 2) NOD IL-10^-/- mice as an acute motor axonal neuropathy (AMAN)-like model best employed over a limited time frame, and 3) NOD WT mice as an AMAN model with mild clinical signs and lesions. Taken together these data demonstrate that C. jejuni strain genotype, host genotype and antibiotic treatment affect GBS disease outcomes in mice and that many disease phenotypes are possible.

Healthy obesity as an intermediate state of risk: a critical review

Obesity is a top public health priority but interventions to reverse the condition have had limited success. About one-in-three obese adults are free of metabolic risk factor clustering and are considered 'healthy', and much attention has focused on the implications of this state for obesity management. Areas covered: We searched for individual studies, systematic reviews, and meta-analyses which examined correlates and outcomes of metabolically healthy obesity. We discuss the key roles of fat distribution and physical activity in determining healthy vs. unhealthy obesity and report a greatly increased risk of incident type 2 diabetes associated with healthy obesity vs. healthy normal weight, among other outcomes. We argue that despite inconsistencies in the definition, patterns across studies clearly show that healthy obesity is a state of intermediate disease risk. Expert commentary: Given the current state of population-level evidence, we conclude that obesity and metabolic dysfunction are inseparable and that healthy obesity is best viewed only as a state of relative health but not of absolute health. We recommend that weight loss through energy restriction be a stand-alone target in addition to increased physical activity for minimising risk of future disease.

Dynapenic obesity and the risk of incident Type 2 diabetes: the English Longitudinal Study of Ageing

AIM

Obesity is a well-established risk factor for developing Type 2 diabetes. Evidence suggests that sarcopenia, the age-related decline in muscle mass and strength, may exacerbate diabetes risk in obese individuals. The aim of this study was to determine the combined effect of obesity and low muscle strength, dynapenia, on the risk of incident Type 2 diabetes in older adults.

METHODS

Participants were 5953 (1670 obese) men and women from the English Longitudinal Study of Ageing without known Type 2 diabetes at baseline and for whom handgrip strength, biochemical and other clinical data were collected. A diagnosis of Type 2 diabetes was recorded from self-reported physician diagnosis over 6 years.

RESULTS

For each unit increase in grip strength, there was a reduction in diabetes risk (age-, sex- and BMI adjusted HR; 0.98; 95% CI 0.96-0.99). The risk of Type 2 diabetes was elevated in all obese participants, but was greatest in those with low handgrip strength (HR = 4.93, 95% CI 2.85, 8.53) compared with non-obese individuals with high handgrip strength. Eleven per cent of the sample met the threshold for weakness (handgrip strength: men < 26 kg; women < 16 kg) that was associated with elevated Type 2 diabetes risk in obese (HR = 3.57, 95% CI 2.04, 6.24) but not in non-obese (HR = 0.86, 95% CI, 0.44, 1.68) compared with normal/non-obese participants.

CONCLUSION

Dynapenic obesity, determined by high BMI and low handgrip strength, is associated with increased risk of incident Type 2 diabetes in older people.

Metabolically healthy obesity and risk of incident type 2 diabetes: a meta-analysis of prospective cohort studies

The risk of type 2 diabetes among obese adults who are metabolically healthy has not been established. We systematically searched Medline (1946-August 2013) and Embase (1947-August 2013) for prospective studies of type 2 diabetes incidence (defined by blood glucose levels or self-report) among metabolically healthy obese adults (defined by body mass index [BMI] and normal cardiometabolic clustering, insulin profile or risk score) aged ≥18 years at baseline. We supplemented the analysis with an original effect estimate from the English Longitudinal Study of Ageing (ELSA), with metabolically healthy obesity defined as BMI ≥ 30 kg m(-2) and <2 of hypertension, impaired glycaemic control, systemic inflammation, adverse high-density lipoprotein cholesterol and adverse triglycerides. Estimates from seven published studies and ELSA were pooled using random effects meta-analyses (1,770 healthy obese participants; 98 type 2 diabetes cases). The pooled adjusted relative risk (RR) for incident type 2 diabetes was 4.03 (95% confidence interval = 2.66-6.09) in healthy obese adults and 8.93 (6.86-11.62) in unhealthy obese compared with healthy normal-weight adults. Although there was between-study heterogeneity in the size of effects (I(2)  = 49.8%; P = 0.03), RR for healthy obesity exceeded one in every study, indicating a consistently increased risk across study populations. Metabolically healthy obese adults show a substantially increased risk of developing type 2 diabetes compared with metabolically healthy normal-weight adults. Prospective evidence does not indicate that healthy obesity is a harmless condition.

The Campylobacter jejuni CiaD effector protein activates MAP kinase signaling pathways and is required for the development of disease

Background

Enteric pathogens utilize a distinct set of proteins to modulate host cell signaling events that promote host cell invasion, induction of the inflammatory response, and intracellular survival. Human infection with Campylobacter jejuni, the causative agent of campylobacteriosis, is characterized by diarrhea containing blood and leukocytes. The clinical presentation of acute disease, which is consistent with cellular invasion, requires the delivery of the Campylobacter invasion antigens (Cia) to the cytosol of host cells via a flagellar Type III Secretion System (T3SS). We identified a novel T3SS effector protein, which we termed CiaD that is exported from the C. jejuni flagellum and delivered to the cytosol of host cells.

Results

We show that the host cell kinases p38 and Erk 1/2 are activated by CiaD, resulting in the secretion of interleukin-8 (IL-8) from host cells. Additional experiments revealed that CiaD-mediated activation of p38 and Erk 1/2 are required for maximal invasion of host cells by C. jejuni. CiaD contributes to disease, as evidenced by infection of IL-10 knockout mice. Noteworthy is that CiaD contains a Mitogen-activated protein (MAP) kinase-docking site that is found within effector proteins produced by other enteric pathogens. These findings indicate that C. jejuni activates the MAP kinase signaling pathways Erk 1/2 and p38 to promote cellular invasion and the release of the IL-8 pro-inflammatory chemokine.

Conclusions

The identification of a novel T3SS effector protein from C. jejuni significantly expands the knowledge of virulence proteins associated with C. jejuni pathogenesis and provides greater insight into the mechanism utilized by C. jejuni to invade host cells.

Physician-patient interactions and outcomes in systemic lupus erythematosus (SLE): a conceptual model

Objective

The objective was to develop a conceptual model illustrating the relationships between the physician-patient relationship and patient outcomes, including health status and regimen satisfaction, in systemic lupus erythematosus (SLE).

Methods

This was a cross-sectional survey of a geographically diverse sample of adults with SLE in the United States. Patients completed a Web-based survey that focused on physician interactions, clinical management, and patient outcomes, including patient perception of treatment regimen and health status. All survey variables related to physician interactions and patient perceptions of their health and satisfaction were evaluated for incorporation into a patient-centered model using cluster analysis. Structural equation modeling (SEM) was conducted to assess the inter-relationships observed among the variables to inform the development of a conceptual model of SLE patient-centered care.

Results

A total of 302 SLE patients completed the survey. The majority of patients were female (94.3%) with a mean age of 46 years. The cluster analysis resulted in six main factors: 1) physician interactions, 2) current health and hope, 3) satisfaction with treatment, 4) bedside manner, 5) discussion of lupus impacts during physician visits, and 6) steroid treatment. The significant relationships among the factors showed that positive physician interactions, such as including the patient in treatment decisions, were associated with higher satisfaction with treatment regimen and patients feeling that SLE was well controlled, a more favorable perception of current health, and being more hopeful about future health. Among the components of physician interactions, setting goals with patients is particularly important, as this was significantly associated with the patient being more hopeful about future health. Being steroid free was significantly related to higher treatment satisfaction.

Conclusion

The study findings informed a conceptual model of SLE patient-centered care that may be used to create more targeted education programs in the management of SLE, with the goal to improve patient outcomes.

Genetic diversity in Campylobacter jejuni is associated with differential colonization of broiler chickens and C57BL/6J IL10-deficient mice

Previous studies have demonstrated that Campylobacter jejuni, the leading causative agent of bacterial food-borne disease in the USA, exhibits high-frequency genetic variation that is associated with changes in cell-surface antigens and ability to colonize chickens. To expand our understanding of the role of genetic diversity in the disease process, we analysed the ability of three C. jejuni human disease isolates (strains 11168, 33292 and 81-176) and genetically marked derivatives to colonize Ross 308 broilers and C57BL/6J IL10-deficient mice. C. jejuni colonized broilers at much higher efficiency (all three strains, 23 of 24 broilers) than mice (11168 only, 8 of 24 mice). C. jejuni 11168 genetically marked strains colonized mice at very low efficiency (2 of 42 mice); however, C. jejuni reisolated from mice colonized both mice and broilers at high efficiency, suggesting that this pathogen can adapt genetically in the mouse. We compared the genome composition in the three wild-type C. jejuni strains and derivatives by microarray DNA/DNA hybridization analysis; the data demonstrated a high degree of genetic diversity in three gene clusters associated with synthesis and modification of the cell-surface structures capsule, flagella and lipo-oligosaccharide. Finally, we analysed the frequency of mutation in homopolymeric tracts associated with the contingency genes wlaN (GC tract) and flgR (AT tracts) in culture and after passage through broilers and mice. C. jejuni adapted genetically in culture at high frequency and the degree of genetic diversity was increased by passage through broilers but was nearly eliminated in the gastrointestinal tract of mice. The data suggest that the broiler gastrointestinal tract provides an environment which promotes outgrowth and genetic variation in C. jejuni; the enhancement of genetic diversity at this location may contribute to its importance as a human disease reservoir.

Multiple factors interact to produce responses resembling spectrum of human disease in Campylobacter jejuni infected C57BL/6 IL-10-/- mice

BACKGROUND

Campylobacter jejuni infection produces a spectrum of clinical presentations in humans--including asymptomatic carriage, watery diarrhea, and bloody diarrhea--and has been epidemiologically associated with subsequent autoimmune neuropathies. This microorganism is genetically variable and possesses genetic mechanisms that may contribute to variability in nature. However, relationships between genetic variation in the pathogen and variation in disease manifestation in the host are not understood. We took a comparative experimental approach to explore differences among different C. jejuni strains and studied the effect of diet on disease manifestation in an interleukin-10 deficient mouse model.

RESULTS

In the comparative study, C57BL/6 interleukin-10-/- mice were infected with seven genetically distinct C. jejuni strains. Four strains colonized the mice and caused disease; one colonized with no disease; two did not colonize. A DNA:DNA microarray comparison of the strain that colonized mice without disease to C. jejuni 11168 that caused disease revealed that putative virulence determinants, including loci encoding surface structures known to be involved in C. jejuni pathogenesis, differed from or were absent in the strain that did not cause disease. In the experimental study, the five colonizing strains were passaged four times in mice. For three strains, serial passage produced increased incidence and degree of pathology and decreased time to develop pathology; disease shifted from watery to bloody diarrhea. Mice kept on an ~6% fat diet or switched from an approximately 12% fat diet to an approximately 6% fat diet just before infection with a non-adapted strain also exhibited increased incidence and severity of disease and decreased time to develop disease, although the effects of diet were only statistically significant in one experiment.

CONCLUSION

C. jejuni strain genetic background and adaptation of the strain to the host by serial passage contribute to differences in disease manifestations of C. jejuni infection in C57BL/6 IL-10-/- mice; differences in environmental factors such as diet may also affect disease manifestation. These results in mice reflect the spectrum of clinical presentations of C. jejuni gastroenteritis in humans and contribute to usefulness of the model in studying human disease.

Genetic background of IL-10(-/-) mice alters host-pathogen interactions with Campylobacter jejuni and influences disease phenotype

We hypothesized that particular genetic backgrounds enhance rates of colonization, increase severity of enteritis, and allow for extraintestinal spread when inbred IL-10(-/-) mice are infected with pathogenic C. jejuni. Campylobacter jejuni stably colonized C57BL/6 and NOD mice, while congenic strains lacking IL-10 developed typhlocolitis following colonization that mimicked human campylobacteriosis. However, IL-10 deficiency alone was not necessary for the presence of C. jejuni in extraintestinal sites. C3H/HeJ tlr4(-/-) mice that specifically express the Cdcs1 allele showed colonization and limited extraintestinal spread without enteritis implicating this interval in the clinical presentation of C. jejuni infection. Furthermore, when the IL-10 gene is inactivated as in C3Bir tlr4(-/-) IL-10(-/-) mice, enteritis and intensive extraintestinal spread were observed, suggesting that clinical presentations of C. jejuni infection are controlled by a complex interplay of factors. These data demonstrate that lack of IL-10 had a greater effect on C. jejuni induced colitis than other immune elements such as TLR4 (C3H/HeJ, C3Bir IL-10(-/-)), MHC H-2g7, diabetogenic genes, and CTLA-4 (NOD) and that host genetic background is in part responsible for disease phenotype. C3Bir IL-10(-/-) mice where Cdcs1 impairs gut barrier function provide a new murine model of C. jejuni and can serve as surrogates for immunocompromised patients with extraintestinal spread.

Development of a fibre optic goniometer system to measure lumbar and hip movement to detect activities and their lumbar postures

If sitting postures influence the risk of developing low back pain then it is important that quantification of sedentary work activities and simultaneous measurement of lumbar postural characteristics takes place. The objective of this study was to develop a system for identifying activities and their associated lumbar postures using fibre optic goniometers (FOGs). Five student subjects wore two FOGs attached to the lumbar spine and hip for 8 min while being recorded using a video camera when sitting, standing and walking. Observer Software was used to code the video recording, enabling the sagittal movement characteristics of each FOG to be described for individual activities. Results indicated that each activity produced unique data, and could be independently identified from their motion profiles by three raters (k = 1). The data will be used to develop algorithms to automate the process of activity detection. This system has the potential to measure behaviour in non-clinical settings.

C57BL/6 and congenic interleukin-10-deficient mice can serve as models of Campylobacter jejuni colonization and enteritis

Campylobacter jejuni is a globally distributed cause of human food-borne enteritis and has been linked to chronic joint and neurological diseases. We hypothesized that C. jejuni 11168 colonizes the gastrointestinal tract of both C57BL/6 mice and congenic C57BL/6 interleukin-10-deficient (IL-10(-/-)) mice and that C57BL/6 IL-10(-/-) mice experience C. jejuni 11168-mediated clinical signs and pathology. Individually housed mice were challenged orally with C. jejuni 11168, and the course of infection was monitored by clinical examination, bacterial culture, C. jejuni-specific PCR, gross pathology, histopathology, immunohistochemistry, and anti-C. jejuni-specific serology. Ceca of C. jejuni 11168-infected mice were colonized at high rates: ceca of 50/50 wild-type mice and 168/170 IL-10(-/-) mice were colonized. In a range from 2 to 35 days after infection with C. jejuni 11168, C57BL/6 IL-10(-/-) mice developed severe typhlocolitis best evaluated at the ileocecocolic junction. Rates of colonization and enteritis did not differ between male and female mice. A dose-response experiment showed that as little as 10(6) CFU produced significant disease and pathological lesions similar to responses seen in humans. Immunohistochemical staining demonstrated C. jejuni antigens within gastrointestinal tissues of infected mice. Significant anti-C. jejuni plasma immunoglobulin levels developed by day 28 after infection in both wild-type and IL-10-deficient animals; antibodies were predominantly T-helper-cell 1 (Th1)-associated subtypes. These results indicate that the colonization of the mouse gastrointestinal tract by C. jejuni 11168 is necessary but not sufficient for the development of enteritis and that C57BL/6 IL-10(-/-) mice can serve as models for the study of C. jejuni enteritis in humans.

Effect of safflower oil, flaxseed oil, monensin, and vitamin E on concentration of conjugated linoleic acid in bovine milk fat

Conjugated linoleic acid (CLA) refers to a mixture of conjugated octadecadienoic acids of predominantly ruminant origin. The main isomer in bovine milk fat is the cis-9, trans-11 CLA. Interest in CLA increased after the discovery of its health-promoting properties, including potent anticarcinogenic activity. Two experiments were conducted to evaluate dietary strategies aimed at increasing the concentration of CLA in bovine milk fat. Both experiments were organized as a randomized complete block design with a repeated measures treatment structure. In Experiment 1, 28 Holstein cows received either a control diet or one of 3 treatments for a period of 2 wk. The control diet consisted of 60% forage (barley silage, alfalfa silage, and alfalfa hay) and 40% concentrate on a dry matter (DM) basis, fed as a total mixed ration (TMR). The concentrate was partially replaced in the treatment groups with 24 ppm of monensin (MON), 6% of DM safflower oil (SAFF), or 6% of DM safflower oil plus 24 ppm of monensin (SAFF/M). Average cis-9, trans-11 CLA levels in milk fat after 2 wk of feeding were 0.45, 0.52, 3.36, and 5.15% of total fatty acids for control, MON, SAFF, and SAFF/M, respectively. In Experiment 2, 62 Holstein cows received either a control diet or one of 5 treatment diets for a period of 9 wk. The control diet consisted of 60% forage (barley silage, alfalfa silage, and alfalfa hay) and 40% concentrate on a DM basis, fed as a TMR. The concentrate was partially replaced in the treatment groups with 6% of DM safflower oil (SAFF), 6% of DM safflower oil plus 150 IU of vitamin E/kg of DM (SAFF/E), 6% of DM safflower oil plus 24 ppm of monensin (SAFF/M), 6% of DM safflower oil plus 24 ppm of monensin plus 150 IU of vitamin E/kg of DM (SAFF/ME), or 6% of DM flaxseed oil plus 150 IU of vitamin E/kg of DM (FLAX/E). Average cis-9, trans-11 CLA levels during the treatment period were 0.68, 4.12, 3.48, 4.55, 4.75, and 2.80% of total fatty acids for control, SAFF, SAFF/E, SAFF/M, SAFF/ME, and FLAX/E, respectively. The combination of safflower oil with monensin was particularly effective at increasing milk fat CLA. The addition of vitamin E to the diet partially prevented the depression in milk fat associated with oilseed feeding, but had no significant effect on the concentration of CLA in milk.

Evidence to support horses as natural intermediate hosts for Sarcocystis neurona

Opossums (Didelphis spp.) are the definitive host for the protozoan parasite Sarcocystis neurona, the causative agent of equine protozoal myeloencephalitis (EPM). Opossums shed sporocysts in feces that can be ingested by true intermediate hosts (cats, raccoons, skunks, armadillos and sea otters). Horses acquire the parasite by ingestion of feed or water contaminated by opossum feces. However, horses have been classified as aberrant intermediate hosts because the terminal asexual sarcocyst stage that is required for transmission to the definitive host has not been found in their tissues despite extensive efforts to search for them [Dubey, J.P., Lindsay, D.S., Saville, W.J., Reed, S.M., Granstrom, D.E., Speer, C.A., 2001b. A review of Sarcocystis neurona and equine protozoal myeloencephalitis (EPM). Vet. Parasitol. 95, 89-131]. In a 4-month-old filly with neurological disease consistent with EPM, we demonstrate schizonts in the brain and spinal cord and mature sarcocysts in the tongue and skeletal muscle, both with genetic and morphological characteristics of S. neurona. The histological and electron microscopic morphology of the schizonts and sarcocysts were identical to published features of S. neurona [Stanek, J.F., Dubey, J.P., Oglesbee, M.J., Reed, S.M., Lindsay, D.S., Capitini, L.A., Njoku, C.J., Vittitow, K.L., Saville, W.J., 2002. Life cycle of Sarcocystis neurona in its natural intermediate host, the raccoon, Procyon lotor. J. Parasitol. 88, 1151-1158]. DNA from schizonts and sarcocysts from this horse produced Sarcocystis specific 334bp PCR products [Tanhauser, S.M., Yowell, C.A., Cutler, T.J., Greiner, E.C., MacKay, R.J., Dame, J.B., 1999. Multiple DNA markers differentiate Sarcocystis neurona and Sarcocystis falcatula. J. Parasitol. 85, 221-228]. Restriction fragment length polymorphism (RFLP) analysis of these PCR products showed banding patterns characteristic of S. neurona. Sequencing, alignment and comparison of both schizont and sarcocyst DNA amplicons showed 100% identity. Although Koch's postulates have not been demonstrated in this case study, the finding of mature, intact S. neurona schizonts and sarcocysts in the tissues of this single horse strongly suggests that horses have the potential to act as intermediate hosts. Further studies are needed to demonstrate Koch's postulates with repeated transfer of S. neurona between opossums and horses.

Structure of crystal form IX of bovine pancreatic ribonuclease A

The X-ray structure of crystal form IX of bovine pancre- atic ribonuclease A (space group P2(1)2(1)2(1)) is reported at 1.6 A resolution. The structure was refined to an R factor of 15.0% and includes coordinates for two sulfate ions, four methanol molecules and 82 waters. The structure could be superimposed on the highest resolution crystal structure of bovine pancreatic fibonuclease available (in space group P2(1)) with an r.m.s, difference in main-chain atomic positions of 0.51 A. Most of the larger differences between the two structures could be related to crystal lattice contacts. Superposition of the new structure with eight other structures of ribonuclease in six crystal forms resulted in an r.m.s, deviation from the average structure of 0.43 A for all main-chain atoms. This similarity among structures exists in spite of the fact that all nine molecules are in different crystal environments.

Parasitemia in an immunocompetent horse experimentally challenged with Sarcocystis neurona sporocysts

Equine protozoal myeloencephalitis (EPM) is a serious neurological disease of horses in Americans. Most cases are attributed to infection of the central nervous system with Sarcocystis neurona. Parasitemia has not been demonstrated in immunocompetent horses, but has been documented in one immunocompromised foal. The objective of this study was to isolate viable S. neurona from the blood of immunocompetent horses. Horses used in this study received orally administered S. neurona sporocysts (strain SN 37-R) daily for 112 days at the following doses: 100/day for 28 days, followed by 500/day for 28 days, followed by 1000/day for 56 days. On day 98 of the study, six yearling colts were selected for attempted culture of S. neurona from blood, two testing positive, two testing suspect and two testing negative for antibodies against S. neurona on day 84 of the study. Two 10 ml tubes with EDTA were filled from each horse by jugular venipuncture and the plasma fraction rich in mononuclear cells was pipetted onto confluent equine dermal cell cultures. The cultures were monitored weekly for parasite growth for 12 weeks. Merozoites grown from cultures were harvested and tested using S. neurona-specific PCR with RFLP to confirm species identity. PCR products were sequenced and compared to known strains of S. neurona. After 38 days of in vitro incubation, one cell culture from a horse testing positive for antibodies against S. neurona was positive for parasite growth while the five remaining cultures remained negative for parasite growth for all 12 weeks. The Sarcocystis isolate recovered from cell culture was confirmed to be S. neurona by PCR with RFLP. Gene sequence analysis revealed that the isolate was identical to the challenge strain SN-37R and differed from two known strains UCD1 and MIH1. To our knowledge this is the first report of parasitemia with S. neurona in an immunocompetent horse.

Expression and co-expression of the members of the epidermal growth factor receptor (EGFR) family in invasive breast carcinoma

The epidermal growth factor receptor (EGFR) family plays an important role in breast carcinogenesis. Much interest has been focused recently on its members because of their potential role as prognostic indicators in breast cancer and their involvement in cancer therapy. We have evaluated more than 1500 cases of invasive breast carcinoma immunohistochemically using tissue microarray technology to examine the expression of EGFR family receptor proteins. We have found that 20.1 and 31.8% of cases were positive for EGFR and c-erbB-2, respectively, and 45 and 45.1% of tumours overexpressed for c-erbB-3 and c-erbB-4, respectively. The expression of either EGFR or c-erbB-2 was associated with other bad prognostic features and with poor outcome. Neither c-erbB-3 nor c-erbB-4 had any association with survival. c-erbB-2 had an independent prognostic effect on overall and disease-free survival (DFS) in all cases, as well as in the subset of breast carcinoma patients with nodal metastases. Several hetero- and homodimeric combinations have been reported between the EGFR members. Those dimers can evoke diverse signal transduction pathways with variable cellular responses. We stratified cases according to their co-expression of receptors into distinct groups with different receptor-positive combinations. Patients whose tumours co-expressed c-erbB-2 and c-erbB-3, as well as those whose tumours co-expressed EGFR, c-erbB-2 and c-erbB-4 showed an unfavourable outcome compared with other groups, while combined c-erbB-3 and c-erbB-4 expression was associated with a better outcome. In cases showing expression of one family member only (homodimers), we found a significant association between c-erbB-4 homodimer-expressing tumours and better DFS. In contrast, patients with c-erbB-2 homodimer-expressing tumours had a significant poorer DFS compared with other cases. These data imply that the combined profile expression patterns of the four receptor family members together provide more accurate information on the tumour behaviour than studying the expression of each receptor individually.

Phenotypic similarities in bilateral breast cancer

Bilateral breast cancers that develop at similar times in an individual are likely to have been subjected to similar hormonal, environmental and genetic influences during tumourogenesis compared with metachronous tumours. As such, it is possible that tumour phenotype in synchronous bilateral breast cancer may display similar biological characteristics. The aim of this study was to identify phenotypic similarities between synchronous and metachronous bilateral breast cancers which may suggest a common origin. Thirty-three cases of synchronous and 46 cases of metachronous bilateral breast cancer that displayed similar tumour type were analysed for concordance in relation to various histological and immunohistochemical parameters. A higher level of concordance was demonstrated for synchronous cases with the highest level seen for oestrogen receptor. It is likely that this is related to similar tumourogenic pathways occurring at equivalent exposure times to various environmental and hormonal influences, although, in a proportion of cases, inherited genetic factors may play a role.

Identification of carcinoma cells in peripheral blood samples of patients with advanced breast carcinoma using RT-PCR amplification of CK7 and MUC1

We have undertaken a pilot study to attempt to identify circulating carcinoma cells in a series of patients with advanced breast carcinoma, using reverse transcription-polymerase chain reaction (RT-PCR) to amplify mRNA of epithelial specific antigens. Using this method to amplify mRNA of MUC1 and cytokeratin 7 (CK7) the sensitivity of the technique was demonstrated by means of diluted concentrations of "spiked MCF7" cells in whole blood, showing a detection limit of 1 in 10(6) (CK7) and 1 in 10(5) (MUC1). Positive results were obtained from the peripheral blood of all nine female patients with advanced breast cancer for CK7 and eight of the nine patients for MUC1. CK7 was however detected in five of 11 healthy controls (eight females, three males) and MUC1 in one of the 11 controls. None of the control group were positive for both CK7 and MUC1, in contrast to eight of the nine patients with advanced breast carcinoma who were positive for both markers. The RT-PCR method thus appears sufficiently sensitive to identify circulating tumour cells in peripheral blood samples from patients with advanced breast carcinoma. However a high proportion of false-positive results was seen in the control population. More extensive investigation is required before the technique is likely to be of benefit clinically.

Variation of the natural transformation frequency of Campylobacter jejuni in liquid shake culture

Natural transformation, a mechanism that generates genetic diversity in Campylobacter jejuni, was studied in a novel liquid shake culturing system that allowed an approximately 10 000-fold increase in cell density. C. jejuni transformation frequency was analysed in this system under 10 %, 5·0 % and 0·7 % CO2 atmospheres. At 5·0 % and 10 % CO2 concentrations, when purified isogenic chromosomal DNA was used to assess competence, transformation frequency ranged from 10−3 to 10−4 at low cell concentrations and declined as cell density increased. Transformation frequency under a 0·7 % CO2 atmosphere was more stable, maintaining 10−3 levels at high cell densities, and was 10- to 100-fold higher than that under a 10 % CO2 atmosphere. Three of four C. jejuni strains tested under a 5·0 % CO2 atmosphere were naturally competent for isogenic DNA; competent strains demonstrated a lack of barriers to intraspecies genetic exchange by taking up and incorporating chromosomal DNA from multiple C. jejuni donors. C. jejuni showed a preference for its own DNA at the species level, and co-cultivation demonstrated that DNA transfer via natural transformation occurred between isogenic populations during short periods of exposure in liquid medium when cell density and presumably DNA concentrations were low. Transformation frequency during co-cultivation of isogenic populations was also influenced by CO2 concentration. Under a 0·7 % CO2 atmosphere, co-cultivation transformation frequency increased approximately 500-fold in a linear fashion with regard to cell density, and was 1000- to 10 000-fold higher during late-exponential-phase growth when compared to cultures grown under a 10 % CO2 atmosphere.

Prognostic significance of BRCA1 expression in sporadic breast carcinomas

BRCA1 is a tumour suppresser gene frequently mutated in familial breast cancer and thought to influence the progression of sporadic breast cancer. Decreased BRCA1 mRNA and protein expression has been identified in breast cancer cell lines and sporadic breast tumours. Here the prognostic significance of reduced BRCA1 protein expression is investigated in primary operable breast cancer. Immunohistochemical analysis was used to determine the level of BRCA1 protein expression in 100 breast cancers. BRCA1 expression was compared with known prognostic factors and survival to investigate its prognostic significance. BRCA1 nuclear expression was reduced by varying amounts in breast carcinomas. A progressive loss of BRCA1 expression correlated well with higher histological grade (p = 0.002) and an excess of medullary/atypical medullary/grade 3 ductal carcinomas (p = 0.0001). When adjusted for grade, patients with loss of BRCA1 expression had a significantly longer disease-free survival time. Loss of BRCA1 expression associated with high-grade breast tumours suggests that BRCA1 may play an important role in the pathogenesis of sporadic breast cancer.

Short communication: Postruminal infusion of conjugated linoleic acids negatively impacts milk synthesis in Holstein cows

In view of the potential of rumen-protected conjugated linoleic acid (CLA) as a means to increase the CLA content of bovine milk, a study was undertaken to evaluate the effect of synthetic CLA on milk production and composition. Four Holstein cows received abomasal infusion of: 1) control, no lipid infusion, 2) 150 g/d of synthetic CLA, 31.7% cis-9, trans-11; 30.4% trans-10, cis-12, 3) 150 g/d of safflower oil, and 4) 150 g/d of tallow. Infusion was carried out for 20 to 22 h/d for 11-d periods in a 4 x 4 Latin square design. The milk fat concentration of cis-9, trans-11 and trans-10, cis-12 isomers of CLA was significantly increased with infusion of CLA. However, CLA infusion had other unexpected effects on milk production and composition. Milk yield dropped significantly during the period of CLA infusion. Furthermore, as well as the typical depression in milk fat reported with trans-10 isomers of CLA, other negative effects specific to CLA infusion were observed including a drop in lactose concentration and yield, a drop in protein yield, and an elevated somatic cell count. The important difference between synthetically produced CLA and CLA produced naturally in the cow is the much higher proportion of trans-10 isomers of CLA in the former. The results of this study suggest that the extent of enrichment possible for trans-10 isomers of CLA, and hence the usefulness of synthetic CLA for this purpose, may be limited because of unacceptable effects on milk yield and composition.

Expression of p27kip1 in breast cancer and its prognostic significance

p27kip1 is a member of the KIP/CIP family of cyclin-dependent kinase inhibitors and is a negative cell-cycle regulator that is thought to play a role in tumour suppression. Reduced levels of this protein have been observed in a number of human cancers. However, evidence is conflicting as to whether p27kip1 has a role to play in breast cancer, including predicting behaviour and prognosis. The present investigation aimed to provide a definitive study of 830 breast cancer cases with median patient follow-up of 104 months to determine the true prognostic significance, if any. Immunohistochemical analysis of tissue microarrays and three scoring methods were used to assess p27kip1 expression. Univariate analysis showed a significant relationship between reduced p27kip1 expression and increasing tumour grade, nuclear pleomorphism, mitosis, and decreasing tubule formation (all p<0.001). Significant associations between reduced p27, negative oestrogen receptor status, and ductal/no special type tumours were also observed. Survival analysis demonstrated that patients with tumours with high p27kip1 levels had an improved survival compared with those with cancers with low expression. On multivariate analysis, when compared with existing factors, p27kip1 was not, however, an independent prognostic factor. It is concluded that the inverse relationship between p27kip1 levels and histological grade and individual grade components suggests a role for p27kip1 in both cell proliferation and differentiation, but is not clinically useful.

Crystine: fibrous biomolecular material from protein crystals cross-linked in a specific geometry

Cysteine substitutions were engineered on the surface of maltose binding protein to produce crystine fibers, linear polymers of folded protein formed within a crystal. Disulfide bond formation between adjacent protein molecules within the lattice was monitored by X-ray crystallography. The cross-linked crystals were resistant to dissolution in water or neutral buffer solutions, even though the cross-linking was one-dimensional. However, crystine fibers were observed by transmission electron microscopy to dissociate from the crystals in acidic solutions. Some fibers remained associated as two-dimensional bundles or sheets, with a repeat unit along the fibers consistent with the packing of the individual protein molecules in the crystal. Neutralization of the acidic solutions caused the fibers to re-associate as a solid. Crystine threads were drawn out of this solution. In scanning electron microscopy images, many individual fibers could be seen unwinding from the ends of some threads. Crystine fibers are a new type of biomolecular material with potential applications wherever the use of proteins in a fibrous form is desirable, for example, the incorporation of enzymes into cloth or filtration material.

Partial coherence laser interferometry vs conventional ultrasound biometry in intraocular lens power calculations

AIMS

The purpose of the study was to compare optical biometry based on partial coherence laser interferometry (PCLI) principle to conventional ultrasound biometry in the accuracy of intraocular lens (IOL) power calculations. The role of partial coherence laser interferometry in pseudophakic axial length measurement was analysed in the study.

METHODS

In a prospective randomised clinical trial, 100 patients undergoing phacoemulsification cataract surgery were randomised to undergo biometry by either partial coherence laser interferometry (IOL Master) or the applanation ultrasound technique. The IOL material, design and the IOL formula were standardized. The mean error and mean absolute error were calculated and compared using paired t-tests.

RESULTS

One hundred patients were included in this prospective randomised trial, of whom 50 patients underwent optical biometry and 50 patients had biometry by applanation ultrasound. The mean age of patients in the PCLI group was 67 +/- 6 yrs as compared to 71 +/- 8 yrs in the ultrasound group (P > 0.05). The preoperative mean axial length was 23.47 +/- 1.1 mm in the PCLI group (range 20-27.6 mm) and 23.43 +/- 1.2 mm in the ultrasound group with a range of 20.1-27 mm (P > 0.05). The mean absolute error (MAE) in the PCLI group was 0.52 +/- 0.32 D (upper and lower 95% CI 0.62 and 0.42 respectively). The MAE in the ultrasound group was 0.62 +/- 0.4 D (upper and lower CI 0.73 and 0.50 D respectively). Eighty-seven per cent of patients were within +/- 1 D in the PCLI group as compared to 80% in the ultrasound group (P = 0.24). The MAE of axial length difference with optical biometry was 0.13 mm +/- 0.13 SD (range -0.42 to 0.78 mm) in the PCLI group and 0.19 +/- 0.13 mm in the ultrasound group. There was a mean shortening of the eye length in the PCLI group postoperatively. Optical biometry improved the post op refraction by 16% on retrospective IOL power calculations. Eight per cent failed biometry with IOL Master (dense cataracts (4%) and fixation instability due to macular degeneration (4%)).

CONCLUSION

The non contact optical biometry using the partial coherence laser interferometry principle improves the predictive value for postoperative refraction and is a reliable tool in the measurement of intraocular distances in pseudophakic eyes.

Neuroendocrine differentiation and prognosis in breast adenocarcinoma

AIMS

Neuroendocrine differentiation has been detected, and its prognostic value studied, in a number of common human carcinomas. To date there are few detailed studies examining its relevance in breast carcinoma. In this study we evaluate the frequency and prognostic importance of neuroendocrine differentiation in breast adenocarcinoma.

METHODS AND RESULTS

The presence of neuroendocrine differentiation, defined as positive reactivity for three markers, neuron-specific enolase (NSE), chromogranin A and/or synaptophysin, has been evaluated in 99 patients with primary operable breast cancer using standard immunocytochemical techniques. A consecutive cohort of patients were selected from the Nottingham/Tenovus series. Comprehensive patient and tumour records have been maintained, and patients were followed up according to a defined protocol. Eighteen cases were positive for NSE, 10 for chromogranin A and 13 for synaptophysin. Eleven percent were positive with more than one neuroendocrine marker. No significant association was found between neuroendocrine differentiation and tumour size, grade, stage or the prevalence of vascular invasion. There was no significant difference in either overall or disease-free survival between patients with or without neuroendocrine differentiation.

CONCLUSIONS

In this study we confirm that neuroendocrine differentiation can be identified in a subset (10-18%) of human breast carcinomas. This phenomenon appears to have no relationship to established prognostic factors or patient outcome.

3D back shape in normal young adults

In today's climate of evidence based medicine, there is an increasing emphasis on objective assessment to monitor treatment effectiveness. Although spinal posture and back shape are commonly assessed by clinicians, current practice is based on subjective findings and unreliable objective tools. Numerous management protocols aim to improve both posture and shape, however data related to normal back shape is quite scarce. The aim of this study was to investigate normal back shape in young adults, in order to produce normative values against which deformity could be defined. The Integrated Shape Imaging System (ISIS) was used to measure the three-dimensional back shape. A convenience sample of 48 normal adults, aged 18-28 volunteered to participate in this study. A small minority of individuals showed no curve (8%), 55% showed a single curve and the rest showed a double one. Right spinal asymmetry was more frequent than the left (77% to 52%). Mean values and 95% confidence intervals were 14.1 degrees (11.7 degrees-16.5 degrees) for upper Lateral asymmetry, 5.6 degrees (3.3 degrees - 7.9 degrees) for lower lateral asymmetry, 24.9mm (20.6mm -29.2mm) for thoracic kyphosis and 14.9mm (12.5mm -17.2mm) for lumbar lordosis. Increasing upper lateral asymmetry correlated with decreasing thoracic kyphosis (p=0.01). Maximum skin surface angle correlated positively with only upper lateral asymmetry (p<0.0001). Similar topographical interrelationships have been demonstrated in scoliosis. It is important that clinicians in relevant disciplines objectively assess all three dimensions of back shape, as our research shows that changes in one plane are associated with changes in the other two planes.

E-cadherin as a prognostic indicator in primary breast cancer

Epithelial cadherin (E-CD) is a member of the cadherin family of cell adhesion molecules and has been implicated as an invasion suppressor molecule in vitro and in vivo. We analysed 174 breast tumours from the Nottingham/Tenovus Breast Cancer Series immunohistochemically for E-CD expression using the mouse monoclonal antibody HECD-1 (Zymed Laboratories Inc.). In normal epithelial cells E-CD was strongly expressed at cell-cell boundaries. 66% of the breast cancers examined had reduced intensity of E-CD expression with 74% having significant reductions in the proportion of E-CD-positive tumour cells. Using a combined intensity/proportion score, significant associations were found between E-CD expression and tumour type (P </= 0.001). ER status (P = 0.026) and histological grade (P = 0.031). Expression of E-CD was not found to be related to recurrence, distant metastases, lymph node stage, vascular invasion, primary tumour size, prognostic group or survival. Thus E-CD expression in human breast cancer appears to have minimal prognostic value, but may have a role as a phenotypic marker.

A rapid troponin-I-based protocol for assessing acute chest pain

In a prospective randomized open trial with 30-day follow-up, we compared a troponin-I-based protocol to 'standard management' for the diagnosis and risk stratification of patients with acute non-ST-elevation chest pain. Patients with acute chest pain (n=400) were randomized to standard diagnostic tests and management, or a protocol based on the admission ECG and the troponin-I result 6 h after onset of chest pain. Low-risk patients were discharged early from CCU; high-risk patients were treated with medical therapy or referred for in-patient angiography as appropriate. We measured length of CCU stay, and followed all patients for major adverse cardiac events (MACE) of death, non-fatal myocardial infarction (MI), or urgent revascularization during the admission and for 30 days post-discharge. The troponin protocol allowed earlier discharge in the low-risk group (10 vs. 30 h, p<0.001) with no excess of adverse events compared to standard management (3% vs. 5%, p=0.32). It identified a group of patients at moderate risk of cardiac events (15% MACE rate during admission and 30-day follow-up), and a high-risk group (75% MACE rate) more accurately than did standard management. The prognostic power of troponin testing in combination with the admission ECG was higher than with either test used alone. The protocol improved the efficiency of low-risk patient management, and improved patient risk stratification. This study adds to the evidence favouring troponin evaluation as part of the management of acute coronary syndromes.

Analysis of segregation data from selfed progeny of allopolyploids

This paper discusses the inference of parental genotype based on segregation data from selfed progeny of allopolyploids when there is incomplete information about genotypes and when alleles are codominant or null. The distinct alleles that are present in a genotype are assumed to be known, but not the frequency with which they occur. These assumptions may be appropriate when genotypes are deduced from DNA or protein banding patterns on electrophoretic gels. A computer program, SELF, is described that can generate all possible parental genotypes and rank them on the basis of their agreement with the progeny data. The program caters for tetraploids, hexaploids and octoploids. The methods are illustrated using data from a study of the inheritance of isoenzymes in selfed progeny of octoploid strawberry cultivars.

Contribution of the hyperpolarization-activated current (I(h)) to membrane potential and GABA release in hippocampal interneurons

Intrinsic GABAergic interneurons provide inhibitory input to the principal neurons of the hippocampus. The majority of interneurons located in stratum oriens (s.o.) of the CA1 region express the hyperpolarization-activated cation current known as I(h). In an effort to elucidate the role of this current in regulating the baseline excitability of these neurons and its participation in the regulation of the release of GABA onto CA1 pyramidal neurons, we utilized whole cell electrophysiological recordings from both populations of cells. In voltage-clamp experiments, hyperpolarization of the interneuron membrane initiated a large inward current with an estimated activation threshold of 51.6 +/- 7.6 mV and a half-maximal voltage of -73.0 +/- 7.0 mV. This current was blocked by bath application of the I(h) inhibitors ZD 7288 (50 microM) or cesium (2 mM). Current-clamp experiments at the interneuron resting membrane potential (-61.3 +/- 1.2 mV) revealed a significant hyperpolarization, a decrease in the rate of spontaneous action potential discharge, an increase in the cellular input resistance, and the elimination of rebound afterdepolarizations during blockade of I(h) with ZD 7288 (50 microM). The hyperpolarizing effect of ZD 7288 was also substantially larger in interneurons clamped near -80 mV using current injection through the pipette. In addition to neurons exhibiting I(h), recordings were obtained from a small population of s.o. interneurons that did not exhibit this current. These cells demonstrated resting membrane potentials that were significantly more negative (-73.6 +/- 5.5 mV) than those observed in neurons expressing I(h), suggesting that this current contributes to more depolarized membrane potentials in these cells. Recordings from postsynaptic pyramidal neurons demonstrated that blockade of I(h) with ZD 7288 caused a substantial reduction (approximately 43%) in the frequency of spontaneous action potential-dependent inhibitory postsynaptic currents (IPSCs), without altering their average amplitude. However, miniature action-potential-independent IPSC frequency, amplitude, and decay kinetics were unaltered by ZD 7288. These data suggest that I(h) is active at the resting membrane potential in s.o. interneurons and as a result contributes to the spontaneous activity of these cells and to the tonic inhibition of CA1 pyramidal neurons in the hippocampus.

Randomised comparison of antero-lateral versus antero-posterior paddle positions for DC cardioversion of persistent atrial fibrillation

We designed a prospective, randomised, single-blind trial to compare the relative efficacy of antero-lateral versus antero-posterior paddle positions for DC cardioversion of persistent atrial fibrillation. A total of 59 patients were randomised to cardioversion using standard gel pads placed either in the antero-lateral (AL) or antero-posterior (AP) positions. The first synchronised shock was given at 360 J; if this was unsuccessful, a second shock of 360 J was given in the alternative position. We compared cardioversion success rate and energy requirements with each strategy. With the first 360 J DC shock, a significantly greater proportion of patients were restored to sinus rhythm from the antero-lateral position (18/30) compared to the antero-posterior position (10/29) (P=0.048). For those patients remaining in atrial fibrillation, there was no difference in the proportions cardioverted from the antero-lateral position (4/19) compared to the antero-posterior position (5/12) with the second 360 J DC shock (P=0. 22). The total cardioversion success rate was 23/30 (77%) for antero-lateral followed by antero-posterior shocks compared to a success rate of 14/29 (48%) for antero-posterior followed by antero-lateral shocks, and this difference was significant (P=0.024). There was no significant difference in the mean energy delivered for patients randomised to an initial antero-lateral shock (504 J), compared to patients given an initial antero-posterior shock (583 J) (P=0.1). We conclude that the antero-lateral paddle position appears more effective for DC cardioversion of persistent atrial fibrillation.

Randomised double blind trial of oral versus intravenous flecainide for the cardioversion of acute atrial fibrillation

OBJECTIVE

To investigate whether an oral loading dose of flecainide is as safe and effective as intravenous flecainide for the cardioversion of acute atrial fibrillation.

DESIGN

Prospective, randomised, double blind, double placebo study.

SETTING

Cardiac care unit of a large district general hospital in the UK.

PATIENTS AND METHODS

79 patients presenting with symptomatic acute atrial fibrillation: patients were given either intravenous flecainide (n = 39) or a solution of oral flecainide (n = 40), with appropriate placebos. All patients were heparinised during the study.

PRIMARY OUTCOME MEASURES

Safety; mean time to cardioversion; proportion of patients restored to sinus rhythm at two hours and eight hours after treatment. Analysis was by intention to treat.

RESULTS

There were no differences in baseline characteristics between the oral and intravenous groups. Both forms of flecainide were well tolerated, with no adverse clinical events during the study. The mean time to cardioversion was 110 minutes in the oral group and 52 minutes in the intravenous group (p = 0.002). Two hours after treatment, 27 of the 40 patients in the oral group (68%) and 25 of the 39 in the intravenous group (64%) had reverted to sinus rhythm (p = 0.74). Eight hours after treatment, 30 patients in the oral group (75%) and 28 in the intravenous group (72%) had reverted to sinus rhythm (p = 0.76).

CONCLUSIONS

Intravenous flecainide restored sinus rhythm more rapidly than oral flecainide, but at two hours and eight hours after treatment there was no difference in the proportion of patients cardioverted by the two approaches. These results suggest a role for oral loading doses of flecainide in the treatment of acute or symptomatic paroxysmal atrial fibrillation.

A circular mitochondrial plasmid incites hypovirulence in some strains of Cryphonectria parasitica

In the chestnut-blight fungus Cryphonectria parasitica, a plasmid, pCRY1, occurs in the mitochondria of several strains isolated at various locations in the northeastern United States and Canada. The monomer of this plasmid is a 4.2-kb circular double-stranded DNA that has no detectable sequence homology with the 160-kb mitochondrial DNA of Ep155, a standard virulent laboratory strain of C. parasitica. The circular nature and oligomeric characteristics of the plasmid were deduced from the heterogeneous size of plasmid DNA molecules as detected by one- and two-dimensional gel-electrophoresis, the nature and alignment of restriction fragments, and the lack of detectable termini in the nucleotide sequence. The cytoplasmic location of the plasmid was deduced from its co-purification with mitochondria, uniparental (maternal) transmission in sexual crosses, dissociation from the nuclei of the donor strain during its horizontal transfer between vegetatively compatible strains through hyphal anastomoses, and mitochondrial codon usage (UGA = Try). The pCRY1 plasmid contains a long open reading frame that is transcribed and potentially encodes a unique 1214 amino-acid, B-family DNA polymerase similar to those encoded by the LaBelle and Fiji circular mitochondrial plasmids of Neurospora. In this subgroup of proteins, the DTD motif characteristic of B-family DNA polymerases is replaced by TTD. Amino-acid motifs related to those that are characteristic of the 3'-->5' exonuclease domains of B-family DNA polymerases have been located in the amino-terminal portion of the proteins. A comparison of isogenic plasmid-free and plasmid-containing cultures indicates that pCRY1 is an infectious agent that effects a reduction in the pathogenicity of some, but not all, strains of C. parasitica.

c-erbB-4 protein expression in human breast cancer

The Type 1 family of growth factor receptors includes epidermal growth factor receptor (EGFR), c-erbB-2, c-erbB-3 and c-erbB-4. Overexpression of the first two members is associated with poorer prognosis in patients with breast carcinoma. In this study we examined the expression of c-erbB-4 protein using the monoclonal antibody HFR-1. A total of 127 consecutive cases of primary operable invasive breast carcinoma presenting between 1975 and 1977 were studied. All patients were managed by simple mastectomy or conservation surgery with radiotherapy and no adjuvant therapy given. Long-term follow-up was maintained. Routine, formalin-fixed, paraffin-embedded tumour samples were used and sections were stained immunohistochemically using the Duet StreptABC method. Immunoreactivity was classified using a simple semi-quantitative scoring method. Protein expression was generally low but definite positive cytoplasmic, membranous and nuclear reactivity was identified in 58%, 41% and 25% of cases respectively. Expression at all three sites demonstrated significant inverse associations were histological grade. In addition, membrane accentuation correlated inversely with the Nottingham Prognostic Index (NPI), while cytoplasmic reactivity showed a positive association with c-erbB-3 expression. No significant associations were found with disease-free interval or survival. The results of this study demonstrate that higher levels of c-erbB-4 protein expression are associated with a more differentiated histological phenotype in contrast to the other members of the Type 1 family. Larger series with extended follow-up will be required to ascertain definitively the prognostic value of c-erbB-4 expression in breast carcinoma.

A comparative transcript map and candidates for mutant phenotypes in the Tyrp1 (brown) deletion complex homologous to human 9p21-23

The mouse Tyrp1 deletion complex is a valuable resource for high-resolution mapping of genes and phenotypes to the central region of Chromosome (Chr) 4. The distal part of the complex is homologous to human Chr 9p21-23, and we have used the available radiation hybrid maps to identify human transcripts in the region. We localize seven genes to a human YAC contig that spans the full extent of the distal deletion complex and show that the mouse homologs of four of these, including Cer1, map within the complex. On the basis of location and/or expression, we exclude genes as candidates for several known phenotypes in the region and identify a candidate transcript for the neonatal lethal phenotype l(4)Rn2.