Long-term interferon-alpha 2A does not induce sustained hematologic remission in younger patients with essential thrombocythemia

The ability of Interferon alpha (alpha-IFN) to alter the natural history of essential thrombocythemia (ET) and induce sustained hematologic remission would provide further impetus to consider this agent in younger patients with this disease and may influence the decision to commence treatment in asymptomatic patients. This study has failed to demonstrate any sustained hematologic remissions after cessation of long-term (2 years) alpha-IFN administration in a group of 34 female patients with a median age of 41 years (range 14-68) who were considered at intermediate to high risk of thrombotic complications. In the twenty-one patients completing two years of therapy, 13 (62%) had complete hematological responses (CHR; platelet count <400 x 10(9)/L), 7 (33%) partial hematological responses (PHR; platelet count 400-600 x 10(9)/L) and no thrombotic or hemorrhagic complications occurred. In all patients who discontinued alpha-IFN at 2 years, platelet counts rose above the normal range within 1-4 months and the majority required reinstitution of some form of therapy. The inability of long-term alpha-IFN to induce sustained, unmaintained hematologic remission argues strongly against any significant effect on the neoplastic clone at the doses used in this study. This study does, however, confirm the efficacy of long-term alpha-IFN in younger female patients with ET, a group not previously well represented in clinical trials of the agent.

Further evidence for an association between non-insulin-dependent diabetes mellitus and chronic hepatitis C virus infection

Non-insulin-dependent diabetes mellitus (NIDDM) may be associated with chronic hepatitis C virus (HCV) infection. This was studied further in two parts. First, 1,151 patients with HCV-related cirrhosis and 181 patients with hepatitis B virus (HBV)-related cirrhosis, well matched for age, sex, and severity of cirrhosis, were reviewed retrospectively. The prevalence of diabetes mellitus was higher in HCV-related cirrhosis (23.6%) than in HBV-related cirrhosis (9.4%; odds ratio [OR], 2.78; 95% confidence interval [CI], 1.6-4.79; P =.0002). The prevalence of diabetes mellitus was associated closely with the Child-Pugh score (OR, 3.83; 95% CI, 2. 38-6.17; P <.0001) and increasing age (OR, 1.02; 95% CI, 1.00-1.03; P =.0117). Second, 235 patients with biopsy confirmed chronic HBV or HCV underwent an oral glucose tolerance test. Only 1 of 70 patients with chronic viral hepatitis without cirrhosis was diabetic. However, 31 of 127 patients with HCV-related cirrhosis (24.4%) were diabetic compared with 3 of 38 patients with HBV-related cirrhosis (7.9%, P =.0477). The major variables associated with NIDDM were cirrhosis (OR, 14.39; 95% CI, 1.91-108; P =.0096) and male sex (OR, 4.64; 95% CI, 1. 32-16.18; P =.0161). Fasting insulin levels in 30 patients with HCV-related cirrhosis and diabetes mellitus were elevated significantly, which was consistent with insulin resistance. However, acute insulin responsiveness was reduced in all patients with HCV infection and diabetes suggesting concomitant B-cell dysfunction. This study confirms an association between HCV and NIDDM.

Crohn's disease-associated genetic marker is seen in medically unresponsive ulcerative colitis patients and may be associated with pouch-specific complications

PURPOSE

Genetic markers have been used to define subgroups of patients within the broad categories of Crohn's disease and ulcerative colitis that may differ in clinical course and response to medical therapy. The tumor necrosis factor microsatellite haplotype a2blc2d4e1 has been found previously to be present in 24 percent of patients with Crohn's disease and only 5 percent of patients with ulcerative colitis. This study examined associations between this microsatellite haplotype and the postoperative clinical course of patients with ulcerative colitis undergoing ileal pouch-anal anastomosis.

METHODS

As part of a large, controlled, prospective study to correlate genetic markers with clinical phenotypes, tumor necrosis factor microsatellite alleles at five loci (a, b, c, d, and e) were determined from genomic DNA by polymerase chain reaction in 32 patients with a clinical and histopathologic diagnosis of ulcerative colitis who underwent ileal pouch-anal anastomosis for medically unresponsive disease. All patients with ileal pouch-anal anastomosis were also studied prospectively for pouch-specific complications.

RESULTS

The tumor necrosis factor haplotype a2blc2d4e1 was present in 11 patients. Median follow-up was 19 months. Thirteen patients had a pouch-specific complication (12 pouchitis and 1 pouch-perineal fistula). Six of 11 patients (55 percent) with the haplotype had a pouch-specific complication compared with 7 of the 21 patients (33 percent) who did not possess this haplotype (P = 0.22). Median time from surgery to pouch-specific complication was eight months. Patients with the haplotype had a median time to pouch-specific complication of three months, whereas patients without the haplotype had a median time of 11 months (P = 0.04). In addition, 36 percent of patients with the haplotype had chronic pouch complications vs. only 10 percent of patients without the haplotype (P = 0.05).

CONCLUSION

The Crohn's disease-associated tumor necrosis factor haplotype a2blc2d4e1 may define a subgroup of medically unresponsive patients with ulcerative colitis who are predisposed to a higher incidence of pouch-specific complications after ileal pouch-anal anastomosis.

Breast and cervix cancer screening among multiethnic women: role of age, health, and source of care

OBJECTIVE

The aim of this study was to evaluate the relationships between age, health status, access to care, and breast and cervical cancer screening among multiethnic elderly and nonelderly women.

METHODS

A structured telephone survey of a quota sample of 1,420 New York City women from four Hispanic groups (Columbian, Dominican, Puerto Rican, Ecuadorian) and three black groups (U.S., Caribbean, and Haitian) was performed. Outcome measures included "ever" and "recent" self-reported use of mammography, clinical breast examination (CBE), and Pap smears. Logistic regression models assessed the predictors of screening use.

RESULTS

Having a regular source of care significantly predicted all screening use for both elderly and nonelderly, controlling for ethnicity, sociodemographics, health status, access to care, proportion of life in the United States, and cancer attitudes. Elderly women (>/=65 years) were significantly less likely to have ever had (OR = 0.79, 95% CI 0.65-0. 96) and to have recently had (OR = 0.67, 95% CI 0.57-0.79) Pap smears than younger women, controlling for the other variables; being elderly also tended to be an independent predictor of ever and recent mammography and CBE use. Interestingly, there was a trend for health status to act differently in predicting Pap smear use for the two age groups. For younger women, being in poor health increased the odds of Pap smear screening, while for elderly women, being in good health increased the odds of screening.

CONCLUSIONS

Elderly women reported being screened less than younger women; interactions between health status and age need further exploration.

Linkage of Crohn's disease to the major histocompatibility complex region is detected by multiple non-parametric analyses

BACKGROUND

There is evidence for genetic susceptibility to Crohn's disease, and a tentative association with tumour necrosis factor (TNF) and HLA class II alleles.

AIMS

To examine the potential of genetic linkage between Crohn's disease and the MHC region on chromosome 6p.

METHODS

TNF microsatellite markers and, for some families, additional HLA antigens were typed for 323 individuals from 49 Crohn's disease multiplex families to generate informative haplotypes. Non-parametric linkage analysis methods, including sib pair and affected relative pair methods, were used.

RESULTS

Increased sharing of haplotypes was observed in affected sib pairs: 92% (48/52) shared one or two haplotypes versus an expected 75% if linkage did not exist (p=0.004). After other affected relative pairs were included, the significance level reached 0.001. The mean proportion of haplotype sharing was increased for both concordant affected (pi=0.60, p=0.002) and unaffected sib pairs (pi=0.58, p=0. 031) compared with the expected value (pi=0.5). In contrast, sharing in discordant sib pairs was significantly decreased (pi=0.42, p=0. 007). Linear regression analysis using all three types of sib pairs yielded a slope of -0.38 at p=0.00003. It seemed that the HLA effect was stronger in non-Jewish families than in Jewish families.

CONCLUSIONS

All available analytical methods support linkage of Crohn's disease to the MHC region in these Crohn's disease families. This region is estimated to contribute approximately 10-33% of the total genetic risk to Crohn's disease.

Azimilide pharmacokinetics and pharmacodynamics upon multiple oral dosing

This study assessed steady-state azimilide pharmacokinetics and pharmacodynamics in 119 healthy male and female volunteers. Parallel groups of 18-40-year-old subjects received doses of 35, 100, 150 or 200 mg day(-1) for up to 14 days, with 1, 2 or 3 days of loading. Another group of > 55-year-old subjects received 100 mg day(-1) with a 3-day loading regimen. There was a slight overshoot of steady-state (24%) after loading, but concentrations decreased to steady-state by day 7. Mean peak steady-state azimilide concentrations ranged from 186 to 1030 ng mL(-1) across the 35-200 mg day(-1) dose range, while mean trough steady-state azimilide concentrations ranged from 108 to 549 ng mL(-1). Azimilide pharmacokinetics were proportional to dose, except for renal clearance, and did not differ between 18-40-year-old and > 55-year-old subjects. Pharmacodynamics did not differ across dose groups. The mean maximum effect (Emax) ranged from 24 to 28% change in QTc from baseline. The concentration needed to attain one half Emax ranged from 432 to 542 ng mL(-1) across dose groups. Equilibration was rapid between blood and the biophase, with equilibration half-lives of less than 1 min.

Identification and characterization of a zinc finger gene (ZNF213) from 16p13.3

During our search for the familial Mediterranean fever (FMF) gene, we identified by cDNA selection a 1.2 kb cDNA fragment representing a novel human gene that is expressed in a wide variety of tissues. This gene spans approx. 8.0 kb genomic DNA and has seven exons. Its 3' untranslated region contains a long tandem repeat that gives rise to a polymorphism with two alleles of approx. 1.1 kb and 1.0 kb, with the 1.1 kb allele in strong linkage disequilibrium with FMF in patients of different ethnic backgrounds. However, both genetic and mutational analyses have excluded this gene as the one responsible for FMF. The predicted 424 amino acid protein, designated ZNF213, contains three C2H2 zinc fingers, a Kruppel associated A box and a leucine rich motif (LeR domain/SCAN box), strongly suggestive of a transcription factor.

Safe mobilization of normal progenitors in advanced chronic myeloid leukemia with intensive chemotherapy and granulocyte-colony stimulating factor

Twenty-one patients with advanced chronic myeloid leukemia (late chronic phase (n = 8), accelerated phase (n = 11) and blast crisis (n = 2)) were treated with idarubicin, cytarabine, and etoposide followed by G-CSF and subsequent collection of peripheral blood progenitor cells in the early recovery phase. Treatment was reasonably well tolerated with no deaths or intensive care admissions. Despite the advanced phase of disease and heavy pretreatment with cytotoxics and interferon-alfa, 11 of 21 patients (52%) achieved a cytogenetic response. Of the nine major cytogenetic responses (complete (n = 3) and partial (n = 6)), seven achieved adequate progenitor collections for consideration for autologous transplantation. The only predictor of response was disease duration (P = 0.02). With a median follow-up of 1171 days from treatment it appears unlikely that G-CSF contributed to disease progression. Survival post-IcE was predicted by disease stage (P = 0.0001). Intensive chemotherapy followed by G-CSF allowed adequate yields of predominantly Philadelphia chromosome negative progenitor cells to be obtained from one-third of patients with advanced CML.

Using self-efficacy to increase physical activity in patients with heart failure

Increasing self-efficacy is not a state that develops quickly. It is unrealistic to expect that the factors contributing to illness and disability will be modified easily. The home care nurse can positively influence self-efficacy expectations in the heart failure population by creating a supportive environment to perform physical activities (performance mastery), assisting with encouragement and support (verbal persuasion), providing anticipatory guidance and sharing how others perform (vicarious experience), and providing a realistic assessment of a person's abilities (physiologic state). By enhancing self-efficacy, the home care nurse can increase physical activity levels in this population, leading to decreased symptomatology and improved quality of life.

Cytokine mRNA profiles in trypanotolerant and trypanosusceptible cattle infected with the protozoan parasite Trypanosoma congolense: protective role for interleukin-4?

African trypanosomes are important pathogens of both humans and livestock. We investigated the association of cytokine responses with disease susceptibility in Trypanosoma congolense-infected cattle. Changes in interleukin (IL)-1beta, IL-2, IL-4, IL-5, IL-6, IL-12 p40, tumor necrosis factor-alpha (TFN-alpha), CD40L, and transforming growth factor-beta (TGF-beta) gene expression were compared in peripheral blood mononuclear cells of infected trypanotolerant N'Dama (Bos taurus) and trypanosusceptible Boran (Bos indicus) cattle. Results revealed that IL-2 transcription was decreased in both breeds of cattle at 21 days after infection. IL-12 p40 mRNA expression was increased in N'Dama cattle at 21 days after infection and at a later time in Boran cattle. The highest IL-4 mRNA expression was observed at 32 days after infection in N'Dama cattle. IL-6 mRNA expression increased in Boran cattle at 11 days after infection and was elevated at 21 and 32 days after infection in both breeds. Transcripts for IL-5 were barely detectable throughout the experimental period in both Boran and N'Dama cattle. Expression of TNF-alpha, IL-1beta, and TGF-beta mRNA did not change notably during the course of infection. In summary, differences in the expression of IL-4 and IL-6 mRNA were identified between the two breeds of cattle during infection with T. congolense, suggesting a possible protective role for IL-4 and a disease-promoting role for IL-6 in bovine trypanosomosis.

Intra- and extracellular dehydration-induced thirst-related behavior in an amphibian

The behavioral response to dehydration is critical to an animal's survival. Because of their permeable skin, amphibians are particularly sensitive to dehydrating conditions. We tested the hypothesis that different forms of dehydration induce water absorption response (WR) behavior in the desert spadefoot toad, Scaphiopus couchii. First, we determined the behavioral response to intracellular dehydration by treating fully hydrated toads with increasing concentrations of hypertonic solutions of NaCl or sucrose via intraperitoneal injection (i.p.). Animals that were treated to induce intracellular dehydration with either solute exhibited a significant increase in WR behavior compared to vehicle-treated controls. To distinguish that the response was a result of an increased osmotic gradient between the intra- and extracellular compartments, we treated fully hydrated animals i.p. with urea, which freely passes into the intracellular compartment and increases overall animal osmolarity. Urea treatment did not induce WR behavior. To determine the response to extracellular dehydration, the blood volume of fully hydrated toads was reduced via cardiac puncture, and the WR behavior was measured. Animals who had a reduction in blood volume exhibited a significant increase in WR behavior compared to sham-punctured controls. Our results are the first to demonstrate that multiple forms of dehydration can induce thirst-related behavior in amphibians.

Exploring the barriers to cervical screening in an urban Canadian setting

Cervical cancer is potentially one of the most preventable cancers. The benefits of cervical screening come to those who are actually screened. Despite the known value of cervical screening, a significant number of women do not avail themselves of the procedure. This study examined the barriers to cervical screening in an urban Canadian setting. Focus group methodology was used to explore the perspectives of socioeconomically disadvantaged women regarding their access to health care. The sessions were tape-recorded, and subsequent content analysis revealed four broad themes: being able to talk with doctors is important; being treated as a person is important; finding answers to many questions about cancer is important; and having a Pap test is uncomfortable. Implications for practice and program design were highlighted.

Simulation applied to health services: opportunities for applying the system dynamics approach

The aim of this essay is to raise awareness and broaden understanding within the health services community of the system dynamics (SD) simulation approach to policy analysis. The application of simulation in health services is reviewed. A comparison is made between the SD and traditional simulation approaches and is illustrated by considering reductions in waiting times for coronary heart disease treatment. Traditionally, simulation studies have tended to focus on the analysis of localized decisions and therefore on problems orientated towards individual patients. Although these methods are extremely powerful and effective, there is scope for an alternative modelling approach which is based on a more holistic perspective; SD is one such approach. It can assist in the design of robust policies by supporting debate on how the underlying structure might influence the evolutionary behaviour of a system. Using this method we can consider the time variation both of tangibles, such as waiting times and health care costs, and intangibles, such as patient anxiety and the effects of various pressures on purchasing decisions. We propose that SD holds great potential in assisting policy formation in health care.

ORBIS--training nurses worldwide in ophthalmic care

The unique nature of the ORBIS teaching mission is reflected in many arenas. The ORBIS organization recognizes that the nurse's role is critical to achieving their mission of preventing blindness through education, hence the emphasis on nurse education. The roles of the head nurse, nurse educator, staff nurses, and the biomedical engineering department are discussed briefly with emphasis on the needs assessment and the different programs offered to meet the identified needs.

Interaction of the Escherichia coli DnaA protein with bacteriophage lambda DNA

Interaction of the Escherichia coli DnaA (replication initiator) protein with restriction fragments of phage lambda DNA demonstrated differential binding of DnaA along the whole lambda DNA. Interaction of DnaA with the lambda replication region (from the promoter pR to the origin of replication, orilambda) demonstrated a strong binding of DnaA to the region around the p(o) promoter where synthesis of a short antisense oop RNA is initiated. The four sequences protected by DnaA (two 9mers and two 5mers) are not related even to a relaxed DnaA box. The pattern of protection of these four sequences and the location of three DNase I hypersensitive sites in the lambda DNA r strand, together with results of mobility shift assays and electron microscopy studies, may indicate an interaction involving DnaA monomers bound to different DNA positions on one side of the helix and the formation of higher-order nucleoprotein structures. Therefore, it is tempting to suggest that DnaA, in addition to its activity in regulation of replication and transcription, could be considered as a factor which structures certain chromosomal regions.

DnaA-mediated regulation of phage lambda-derived replicons in the absence of pR and Cro function

Bacteriophage lambda-derived replicons can replicate in Escherichia coli cells as plasmids. In the control of replication of these plasmids, an important role was ascribed to the lambda Cro repressor autoregulatory loop. However, the oR/pR-cro-tR-cII' region could be replaced by the ptetA promoter under the control of the TetR repressor, producing plasmid pTClambda. Here, we demonstrate that stable maintenance of pTClambda depends on the host DnaA function because deletion of one of DnaA-binding sequences present in pTClambda resulted in a decrease in the plasmid (pTClambda) copy number and poor maintenance of pTClambda in E. coli. Moreover, in contrast to the replication of the wild-type lambda plasmid, previously found to be positively regulated by DnaA (acting on a relaxed DnaA box situated immediately downstream of the pR promoter), the replication of pTC plasmids (devoid of pR) was found to be negatively regulated by DnaA. Contrary to wild-type lambda plasmids, in cells harboring lambda cro[temperature-sensitive (ts)] or pTClambda (but not pTClambda) plasmid, the lambda replication complex was heat shock resistant; this complex, however, disassembled after inactivation of DnaA function. This disassembly was blocked by DNA gyrase inhibitors. According to our model outlined previously, we propose that the heat shock resistance of the replication complex of lambdacro- plasmids depends on the interaction of the DNA-bound DnaA protein with the DNA-bound lambda replication complex. The replication complex-DnaA-lambda DNA structure may be directly related to the role of DnaA as the Cro-replacing negative regulator of lambdacro- plasmid replication.

Trypanosoma congolense infection of trypanotolerant N'Dama (Bos taurus) cattle is associated with decreased secretion of nitric oxide by interferon-gamma-activated monocytes and increased transcription of interleukin-10

The mechanisms whereby trypanotolerant N'Dama cattle control infection with Trypanosoma congolense are unknown. Previous studies have suggested that the monocytes of N'Dama cattle are more highly activated during infection than those of trypanosusceptible Boran cattle. However, we have recently reported that the monocytes of Boran cattle have a reduced capacity to secrete nitric oxide during trypanosome infection. We therefore evaluated the production of nitric oxide by monocytes of trypanotolerant N'Dama cattle infected with T. congolense in response to interferon-gamma, bacterial lipopolysaccharide or trypanosome antigens. Interferon-gamma-induced nitric oxide production was decreased between days 25 and 76 of infection, while lipopolysaccharide-induced secretion of nitric oxide was increased at days 13 and again at day 76 post-infection. Trypanosome antigens did not elicit nitric oxide production. Analysis of interleukin-10 mRNA transcription in peripheral blood leucocytes revealed an increase at time points that coincided with decreased interferon-gamma-induced nitric oxide synthesis. In contrast, interferon-gamma mRNA expression was not changed during infection while tumour necrosis factor-alpha was slightly reduced at day 32 post-infection. Recombinant interleukin-10 suppressed interferon-gamma-induced nitric oxide and tumour necrosis factor-alpha secretion, but not lipopolysaccharide-induced nitric oxide secretion in cultures of peripheral blood mononuclear cells and monocytes of uninfected cattle. These results suggest that the nitric oxide response of monocytes to IFN-gamma but not lipopolysaccharide, is suppressed during infection. The kinetics of the upregulation of interleukin-10 and its biological activity indicate a possible association with the depression of nitric oxide production and control of tumour necrosis factor-alpha.

Evolution of an enzyme active site: the structure of a new crystal form of muconate lactonizing enzyme compared with mandelate racemase and enolase

Muconate lactonizing enzyme (MLE), a component of the beta-ketoadipate pathway of Pseudomonas putida, is a member of a family of related enzymes (the "enolase superfamily") that catalyze the abstraction of the alpha-proton of a carboxylic acid in the context of different overall reactions. New untwinned crystal forms of MLE were obtained, one of which diffracts to better than 2.0-A resolution. The packing of the octameric enzyme in this crystal form is unusual, because the asymmetric unit contains three subunits. The structure of MLE presented here contains no bound metal ion, but is very similar to a recently determined Mn2+-bound structure. Thus, absence of the metal ion does not perturb the structure of the active site. The structures of enolase, mandelate racemase, and MLE were superimposed. A comparison of metal ligands suggests that enolase may retain some characteristics of the ancestor of this enzyme family. Comparison of other residues involved in catalysis indicates two unusual patterns of conservation: (i) that the position of catalytic atoms remains constant, although the residues that contain them are located at different points in the protein fold; and (ii) that the positions of catalytic residues in the protein scaffold are conserved, whereas their identities and roles in catalysis vary.

Replication and maintenance of lambda plasmids devoid of the Cro repressor autoregulatory loop in Escherichia coli

Plasmids derived from bacteriophage lambda are known as lambda plasmids. These plasmids contain the ori lambda region and lambda replication genes O and P. Typical lambda plasmids also contain the cro gene, the product of which is a repressor of the pR promoter when present at relatively high concentrations. These genes stably maintain the plasmid in Escherichia coli at copy numbers of 20 to 50 per cell. According to a generally accepted model, stable maintenance of lambda plasmids is possible due to the Cro repressor autoregulatory loop (the cro gene is under control of pR). Here we demonstrate that lambda plasmids devoid of the Cro autoregulatory loop can also be stably maintained in E. coli strains. We present data for two such plasmids: pTC lambda 1 in which the pR-cro region has been replaced by the ptetA promoter and the tetR gene (coding for the TetR repressor), and a standard lambda plasmid with inactivated cro gene (lambda cro-null plasmid). Thus, the presence of the Cro repressor autoregulatory loop does not appear to be essential to the maintenance of lambda plasmids in vivo.