The peptide near the C terminus regulates receptor CAR nuclear translocation induced by xenochemicals in mouse liver

In response to phenobarbital (PB) and other PB-type inducers, the nuclear receptor CAR translocates to the mouse liver nucleus (T. Kawamoto et al., Mol. Cell. Biol. 19:6318-6322, 1999). To define the translocation mechanism, fluorescent protein-tagged human CAR (hCAR) was expressed in the mouse livers using the in situ DNA injection and gene delivery systems. As in the wild-type hCAR, the truncated receptor lacking the C-terminal 10 residues (i.e., AF2 domain) translocated to the nucleus, indicating that the PB-inducible translocation is AF2 independent. Deletion of the 30 C-terminal residues abolished the receptor translocation, and subsequent site-directed mutagenesis delineated the PB-inducible translocation activity of the receptor to the peptide L313GLL316AEL319. Ala mutations of Leu313, Leu316, or Leu319 abrogated the translocation of CAR in the livers, while those of Leu312 or Leu315 did not affect the nuclear translocation. The leucine-rich peptide dictates the nuclear translocation of hCAR in response to various PB-type inducers and appears to be conserved in the mouse and rat receptors.

Emergence trap developed to capture adult large pine weevil Hylobius abietis (Coleoptera: Curculionidae) and its parasite Bracon hylobii (Hymenoptera: Braconidae)

A novel type of emergence trap capable of capturing and separating 'live' insect catches is described. The trap was shown to be 96% efficient at capturing newly emergent adult Hylobius abietis Linnaeus on bare ground and at least 82% efficient over stumps on a weedy Sitka spruce clearfell. The trap was more than 80% efficient at capturing Bracon hylobii Ratzeburg, the most commonly found parasite of H. abietis. It was also shown to be effective at capturing adult H. abietis of unknown age (98%), indicating that it could also be used to trap out H. abietis from known areas to estimate on-site overwintering densities. Fifty-four percent of newly emergent weevils were captured within 12 h of release on bare mineral soils. Forty-two percent of unknown age weevils and 52% of parasites were captured within 1 h of their release within the trap. The rapid rates of capture mean that when traps are checked frequently they can be used to reflect accurately temporal patterns of emergence. Its potential for use in control programmes and ecological studies is discussed.

Congenital pseudarthrosis of the tibia treated with free vascularized fibular graft

Management of patients with deformities due to congenital pseudarthrosis of the tibia continues to be controversial. The use of free vascularized fibular grafts in the reconstruction of these deformities appears to be successful in this patient population but is not without potential for significant complications. Long-term evaluation, at least to skeletal maturity, is necessary to judge the success of any procedure done for any pediatric patient. This case illustrates the natural history of the vascularized free fibular graft for congenital pseudarthrosis of the tibia in a young child. Complications of this treatment modality did occur, including probable recurrence and fracture at almost 11 years post-index procedure. However, stable reconstruction leading to fracture union was achieved, and the patient has resumed full activities with little residual deformity.

Microstructure determination of AOT + phenol organogels utilizing small-angle X-ray scattering and atomic force microscopy

Dry reverse micelles of the anionic twin-tailed surfactant bis(2-ethylhexyl) sulfosuccinate (AOT) dissolved in nonpolar solvents spontaneously form an organogel when p-chlorophenol is added in a 1:1 AOT:phenol molar ratio. The solvents used were benzene, toluene, m-xylene, 2,2,4-trimethylpentane (isooctane), decane, dodecane, tetradecane, hexadecane, and 2,6,10,14-tetramethylpentadecane (TMPD). The proposed microstructure of the gel is based on strands of stacked phenols linked to AOT through hydrogen bonding. Small-angle X-ray scattering (SAXS) spectra of the organogels suggest a characteristic length scale for these phenol-AOT strands that is independent of concentration but dependent on the chemical nature of the nonpolar solvent used. Correlation lengths determined from the SAXS spectra indicate that the strands self-assemble into fibers. Direct visualization of the gel in its native state is accomplished by using tapping mode atomic force microscopy (AFM). It is shown that these organogels consist of fiber bundle assemblies. The SAXS and AFM data reinforce the theory of a molecular architecture consisting of three length scales-AOT/phenolic strands (ca. 2 nm in diameter) that self-assemble into fibers (ca. 10 nm in diameter), which then aggregate into fiber bundles (ca. 20-100 nm in diameter) and form the organogel.

Viral co-infection does not reduce the efficacy of vaccination against non-typeable Haemophilus influenzae middle ear infection in a rat model

The mucosal vaccination of rodents with killed non-typeable Haemophilus influenzae (NTHi) has been previously shown to enhance live NTHi clearance following middle ear challenge. This study assessed the efficacy of mucosal anti-NTHi vaccination during a concomitant viral infection of the respiratory tract. Animals were mucosally immunised with killed NTHi by intra-Peyer's patch primary inoculation and lung (intratracheal) boost. At the time of both immunisations rats were also infected intra-nasally with Sendai virus. Concomitant Sendai virus infection did not influence the efficacy of anti-NTHi vaccination mediated clearance of NTHi from the middle ear. This would suggest that immunisation strategies to prevent bacterial middle ear infection would be effective despite the presence of concomitant viral agents.

An examination of methods for risk-adjustment of rehospitalization rates

This study examines three methods of conducting risk-adjustment to determine if the choice of method results in different conclusions about comparative mental health center performance. The three methods of risk-adjustment are stratification-weighting, logistic regression without interaction effects, and logistic regression with interaction effects. The dependent variable of interest is psychiatric rehospitalization within 14-60 days of discharge to a community mental health center. Subjects are adults discharged in fiscal year 1998 from inpatient psychiatric care to a designated community mental health center in Oklahoma. Using each method, we examine the mental health centers to determine whether their rehospitalization rates are significantly greater than, less than, or not different from, expected. Results show that, for some agencies, method of risk adjustment leads to different conclusions about center performance. Results are discussed with respect to identifying the preferred method of risk-adjustment, study limitations, and next steps in developing risk-adjustment technology and applications.

Dentists' perceived stress and its relation to perceptions about anxious patients

Dentists' perceptions about the stressfulness of dental practice, their perceptions about dental anxiety and its management were surveyed in a descriptive study. A mailed questionnaire was completed by 216 randomly selected Danish private dentists. Of these, nearly 60% perceived dentistry as more stressful than other professions. Dentist perceptions of the most intense stressors were (ranked): 1) running behind schedule, 2) causing pain, 3) heavy work load, 4) late patients and 5) anxious patients. Bivariate odds ratio (OR) analyses were undertaken to check for associations of perceived stress and other dentist variables with perceptual outcomes about anxious patients. Signs of dental anxiety were reported to be less often spotted by older (> or = 52 yr) dentists (OR=3.1) who perceived their job stress to be greater than that of other professionals (OR=3.2). Perceived causes of dental anxiety (1st, 2nd or 3rd choices tallied and then ranked) were 1) fear of pain, 2) trauma in dental treatment, 3) general psychological problems, 4) shame about dental status and 5) economic excuses. Dentists who reported that dental anxiety was primarily the result of general psychological problems in patients, usually had solo (OR=2.4) practices older than 18 years (OR=2.6) and reported high perceived stress (OR=2.2). Adjusted odds ratios for these two dentist perception outcomes about anxious patients generally improved strength of associations and confidence intervals. There were no meaningful differences by practice location or perceived public image. Also, there was no significant association between the use of pharmacological strategies for anxiety and the perceived stress of dentists. Nearly all dentists talked with anxious patients as their main treatment strategy. It was concluded that psychosocial aspects of dental practice have meaningful and often adverse associations with dentist perceptions about anxious patients. Some dentists appeared to require more knowledge about dental anxiety and managing their own stress.

Nuclear receptor CAR as a regulatory factor for the sexually dimorphic induction of CYB2B1 gene by phenobarbital in rat livers

The nuclear receptor constitutive active receptor (CAR) translocates into liver nuclei after phenobarbital (PB) treatment, and activates the conserved enhancer called the PB-response element module (PBREM) found in CYP2B genes. We have examined whether CAR regulates the dimorphic induction by PB of the CYP2B1 gene in Wistar Kyoto (WKY) rats. Northern blot analysis showed that PB induced CYP2B1 mRNA in male WKY rats but not female rats. An in situ injected PBREM-luciferase reporter gene was activated by PB only in the male livers. Western blot analysis revealed extremely low levels of CAR in the cytosols of female livers compared with male counterparts. CAR was accumulated in the liver nucleus of male rats in response to PB treatment, whereas the receptor was barely detectable in the liver nuclei of PB-induced females. These sexually dimorphic responses of PBREM and CAR to PB treatment were not observed with Fisher 344 rats, in which CYP2B1 mRNA was induced in both sexes. Thus, these results indicate that CAR is a regulatory factor that leads to the sexual dimorphic induction of CYP2B1 gene in WKY rats.

Cyclin/Cdk complexes: their involvement in cell cycle progression and mitotic division

DNA replication and mitosis are dependent on the activity of cyclin-dependent protein kinase (CDK) enzymes, which are heterodimers of a catalytic subunit with a cyclin subunit. Cyclin binding to specific individual proteins is thought to provide potential substrates to Cdk. Protein binding by cyclins is assessed in terms of its mechanisms and biological significance, using evidence from diverse organisms including substrate specificity in animal Cdk enzymes containing D-, A-, and B-type cyclins and extensive cyclin gene manipulations in yeasts. Assembly of protein complexes with cyclin/Cdk is noted and the capacity of the cyclin-dependent kinase subunit Cks, in such complex, to extend the range of Cdk substrates is documented and discussed in terms of cell cycle regulation. Cell cycle progression involves changing abundance of individual cyclins, due to changing rates of their transcription or proteolysis, with consequent changes in the substrates of CDK through the cell cycle. Some overlap of the functions of individual cyclins in vivo has been identified by cyclin deletions and is suggested to follow a pattern in which cyclins can commonly complete functions initiated by the preceding cyclins well enough to preserve viability as groups of cyclins are removed by proteolysis. Cyclin accumulation is particularly important in terminating the G1 phase, when it raises CDK activity and starts events leading to DNA replication. It is suggested that plants share this mechanism. The distribution of cyclins and Cdk in maize root tip cells during mitosis and cytokinesis indicates the presence of Cdk1 (Cdc2a) and cyclin CycB1zm;2 at the mature and disassembling preprophase band and the presence of CycB1zm;2 at condensing and condensed chromosomes. Both observations correlate with the earlier-reported capacity of injected metaphase cyclin/CDK to accelerate preprophase band disassembly and chromosome condensation and with observations of the location of Cdk and cyclins in other laboratories. Additionally CycB1zm;2 is seen at the nuclear envelope during its breakdown, which correlates with an acceleration of the process by injected metaphase cyclin B/CDK. A phenomenon possibly unique to the plant kingdom is the persistence of mitotic cyclins after anaphase. Participation of cyclins in cytokinesis is indicated by the concentration of the mitotic cyclin CycA1;zm;1 at the phragmoplast. It is suggested that cyclins have a general function of spatially focusing Cdk activity and that in the plant cell the concentrations of cyclins are important mediators of CDK activity at the cytoskeleton, chromosomes, spindle, nuclear envelope, and phragmoplast.

Neuromodulation for chronic refractory angina

Neuromodulation is the use of therapies which alter the relationship between the heart, its autonomic innervation and the central nervous system with the objective of reducing the ischaemic burden and diminishing the perception of angina.

Effects of cognitive therapy on psychological symptoms and social functioning in residual depression

BACKGROUND

About 30% of psychiatric out-patients with major depression demonstrate partial remission.

AIMS

To explore whether the addition of cognitive therapy (CT) had any differential effect on residual symptoms or social adjustment.

METHOD

Patients with residual symptoms of major depression (n=158) were randomised to receive clinical management (CM) alone, or CM plus 18 sessions of CT. Subjects' depressive symptoms and social functioning were assessed regularly over 16 months.

RESULTS

The addition of CT produced statistically significant differential effects on: two out of four measures of overall severity of depression; specific psychological symptoms (guilt, self-esteem and hopelessness); and social functioning (including dependency, interpersonal behaviour and friction).

CONCLUSIONS

In patients showing only partial response to antidepressants, the addition of CT produced modest improvements in social and psychological functioning. The implications for research on the mechanisms of action of CT are discussed.

Measurement of J/psi and psi(2S) polarization in pp collisions at sqrt[s] = 1.8 TeV

We have measured the polarization of J/psi and psi(2S) mesons produced in pp collisions at sqrt[s] = 1.8 TeV, using data collected at the Collider Detector at Fermilab during 1992-1995. The polarization of promptly produced J/psi [psi(2S)] mesons is isolated from those produced in B-hadron decay, and measured over the kinematic range 4 [5.5]<P(T)<20 GeV/c and |y|<0.6. For P(T) greater than or approximately equal 12 GeV/c we do not observe significant polarization in the prompt component.

Placebo-associated remissions in a multicentre, randomized, double-blind trial of interferon gamma-1b for the treatment of metastatic renal cell carcinoma. The Canadian Urologic Oncology Group

OBJECTIVE

To determine the validity of using an historical maximum spontaneous regression rate (reportedly 0-1.1% in those with lung metastases after nephrectomy) in clinical trials of treatments for patients with metastatic renal cell carcinoma (RCC), as the eligibility criteria for most studies will select patients with better performance status (and thus excluding those who are unlikely to respond) and more modern staging methods would potentially reduce the number of false-positives.

PATIENTS AND METHODS

A multicentre randomized,placebo-controlled, double-blind trial was recently completed in which 197 patients with metastatic RCC from 17 study centres across Canada were randomized to receive placebo or recombinant interferon gamma-1b (60 microg/m2) subcutaneously once every 7 days until disease progression. All tumour responses were validated by an independent response committee unaware of the treatment.

RESULTS

The median (95% confidence interval) overall response rate (complete, CR, and partial, PR) for those on interferon-gamma was 4 (1.4-11.5)% and for those on placebo was 6 (2. 5-13.2)% (P = 0.75). In the six patients who were receiving placebo the CR and PR (three each) was considered to represent spontaneous remission. Of these six patients (aged 44-64 years) five had undergone nephrectomy, one a tumour embolization, four had clear cell carcinoma and one an adenocarcinoma, and all had regression of lung and/or lymph node metastases.

CONCLUSION

The lack of efficacy of interferon-gamma in this trial underlines the importance of continued research to identify alternative therapeutic agents or combinations of agents in phase II studies. However, the threshold response rate for initiating phase III trials should be increased to 18% in the phase II trials, i.e. three times the response rate on placebo.

Catalase immunization from Pseudomonas aeruginosa enhances bacterial clearance in the rat lung

Pseudomonas aeruginosa is a common cause of infection in immunocompromised patients and is the major contributor to morbidity in individuals with cystic fibrosis (CF). The antibiotic resistance shown by this pathogen and morbidity in patients with chronic infection has encouraged investigations into the development of a vaccine. This study reports the purification of a 60 kDa protein, isolated from a mucoid strain of P. aeruginosa, identified by amino acid sequence analysis as the catalase protein (KatA). A rat model of acute P. aeruginosa respiratory infection was used to investigate the immunogenicity of KatA and determine the potential of mucosal immunization with KatA to protect against infection. Immunization regimens compared a single intra-Peyer's patch (IPP) immunization with an IPP primary inoculation followed by an intratracheal boost to the lungs. Mucosal immunization with KatA resulted in significant pulmonary clearance of both homologous (p<0.001) and heterologous (p<0.05) strains of P. aeruginosa. Both immunization regimens enhanced bacterial clearance, increased the rate of recruitment of phagocytes to the bronchoalveoli and induced KatA-specific antibody. However, the regimen that included a boost induced a more effective immune response that also resulted in better clearance of P. aeruginosa from the lungs. Mucosal immunization induced KatA- specific antibodies in the serum and the bronchoalveolar lavage, and KatA-specific lymphocyte proliferation in vitro in cells isolated from the mesenteric lymph nodes of immunized rats. The data presented suggests that KatA has the potential to afford a protective immune response against pulmonary infection by P. aeruginosa

International telementoring: a feasible method of instruction

Since the advent of improved telecommunication technology, greater bandwidth capability, medical robotics, and digital video technology, telemedicine has evolved. Telesurgical telementoring is an advanced form of telemedicine. An experienced surgeon can conduct, guide and mentor a second surgeon from a remote location. The historical method of teaching surgeons new operative techniques is exemplified in residency training: having individuals work with experienced teachers. Unfortunately, it is impractical for these specialized minimally invasive surgeons to travel and proctor generally trained surgeons each time a new surgical technique is developed. Telesurgical telementoring may represent a method to teach and mentor remote surgeons, as well as allow educational opportunities.

Cohort study of the treatment of severe HIV-associated nephropathy with corticosteroids

BACKGROUND

Human immunodeficiency virus-associated nephropathy (HIVAN) results in rapidly progressive azotemia. The effectiveness and safety of corticosteroids in the treatment of HIVAN, however, remains controversial.

METHODS

We conducted a retrospective cohort study of patients with biopsy-proven HIVAN and progressive azotemia who were eligible for corticosteroid treatment and who had no clinical or histologic evidence of an alternative cause of acute renal failure. Selected patients were treated with 60 mg of prednisone for one month, followed by a several-month taper.

RESULTS

Twenty-one eligible patients were identified. Thirteen subjects had received corticosteroid treatment, whereas eight had not. The mean serum creatinine was 6.2 and 6.8 mg/dL, respectively (P > 0.05). The relative risk (95% CI) for progressive azotemia with corticosteroid treatment at three months was 0.20 (0.05, 0.76, P < 0.05). This association remained significant despite adjustment in separate logistical regression analyses for baseline creatinine, 24-hour proteinuria, CD4 count, history of intravenous drug use, hepatitis B, and hepatitis C. In an additional logistic regression model, using backward stepwise selection of the previously mentioned covariates, only corticosteroid treatment (P = 0.02) and baseline serum creatinine (P = 0.10) were retained within the model. In the corticosteroid-treated group, the mean level of proteinuria decreased by 5.5 g/24 hour (P = 0.01). On long-term follow-up, there was no significant difference in the incidence of hospitalizations (1 per 2.1 vs. 1 per 2.3 patient months) or of serious infections (1 per 2.6 vs. 1 per 2.3 patient months), but there was a significantly longer duration of hospitalization in the corticosteroid-treated group (3.2 vs. 2 days per patient month). At six months, only one of the non-corticosteroid-treated patients but seven of the corticosteroid-treated group continued to have independent renal function (P = 0.06). Three of the corticosteroid-treated group continued to have independent function at two years of follow-up.

CONCLUSION

A limited course of corticosteroid therapy in selected patients was beneficial and safe. Further research is required for the role of corticosteroids in the treatment of HIVAN.