8-oxodGTP incorporation by DNA polymerase beta is modified by active-site residue Asn279

To understand how the active site of a DNA polymerase might modulate the coding of 8-oxo-7,8-dihydrodeoxyguanine (8-oxodG), we performed steady-state kinetic analyses using wild-type DNA polymerase beta (pol beta) and two active-site mutants. We compared the coding of these polymerases by calculating the ratio of efficiencies for incorporation of dATP and dCTP opposite 8-oxodG and for incorporation of 8-oxodGTP opposite dA and dC. For wild-type pol beta, there is a 2:1 preference for incorporation of dCTP over dATP opposite 8-oxodG using a 5'-phosphorylated 4-base gap substrate. Mutation of either Asn279 or Arg283 to alanine has almost no effect on the ratio. 8-OxodGTP is preferentially incorporated opposite a template dA (24:1) by wild-type pol beta; mutation of Asn279 to alanine results dramatic change whereby there is preferential incorporation of 8-oxodGTP opposite dC (14:1). This suggests that interactions of 8-oxodGTP with Asn279 in the polymerase active site may alter the conformation of 8-oxodGTP and therefore alter its misincorporation.

The major histocompatibility complex and inflammation

The major histocompatibility complex (MHC) is of major medical interest because of its contribution to transplant rejection and to variation among individuals in susceptibility to a variety of autoimmune disorders. In addition to its role in influencing the propensity for known autoimmune diseases, the MHC contains genes contributing to several other hereditary disorders that are not autoimmune in nature or in which the role of autoimmunity is uncertain. Recently, a cluster of genes encoding inflammation-related proteins were found, and our review focuses on these findings and their clinical relevance.

Antioxidants: their role in pregnancy and miscarriage

The aim of this study was to examine the role of antioxidants within the normal menstrual cycle, in healthy pregnancy, and in women suffering first-trimester miscarriage. The antioxidants chosen comprised of two from peripheral blood-plasma thiol and ceruloplasmin-and two extracellular parameters-superoxide dismustase (SOD) and red cell lysate thiol. We found that antioxidant levels varied little throughout the menstrual cycle. Pregnancies that went successfully to term were associated with increased levels of ceruloplasmin and SOD early in the first trimester. These changes were thought to offer the cell protection from the damage caused by the increased oxidative stress associated with pregnancy. First-trimester miscarriage was associated with significantly reduced levels of SOD. A subgroup of patients who miscarried in their first pregnancy, but whose second pregnancies were successful, had higher levels of plasma thiol and significantly reduced levels of red cell lysate thiol in the on-going pregnancy compared to levels at the time of miscarriage. Miscarriage and pregnancy appear to be associated with increased oxidative stress. In a successful pregnancy, however, changes occurred within the peripheral blood that offered protection from oxidant attack.

Increased expression of the CD11b/CD18 antigen on the surface of peripheral white blood cells in patients with ischemic heart disease: further evidence for smoldering inflammation in patients with atherosclerosis

BACKGROUND

This study examined the availability of the CD11b/CD18 and CD62L antigens on the surface of peripheral blood leukocytes in patients with ischemic heart disease.

METHODS AND RESULTS

The study population included 45 patients with angiographically documented ischemic heart disease admitted to our department of internal medicine and the cardiology department during 1 month (December 1997). Sixty-six healthy members of the hospital medical staff served as control subjects. Another 39 post-trauma patients who were admitted to the emergency room were also evaluated. Patients with ischemic heart disease had significantly (P <.002) higher concentrations of CD11b/CD18 antigen on the surface of their polymorphonuclear leukocytes and monocytes (mean fluorescence intensity of 203 +/- 81 and 261 +/- 75, respectively) compared with the control group (mean fluorescence intensity 158 +/- 68 and 211 +/- 74, respectively) and to the group of patients with acute stress (mean fluorescence intensity of 146 +/- 70 and 200 +/- 22, respectively).

CONCLUSIONS

The presence of increased concentration of CD11b/CD18 suggests that circulating leukocytes are activated in patients with ischemic heart disease. This activation probably reflects the presence of an inflammatory response involving the atherosclerotic lesion and is not merely a result of acute stress.

Occupational therapy with children with pervasive developmental disorders

OBJECTIVE

Although the prevalence of children with pervasive developmental disorders (PDD) has increased, empirical data about the role and practices of occupational therapists have not been reported in the literature. This descriptive study investigated the practice of occupational therapists with children with PDD.

METHOD

A survey was mailed to 500 occupational therapists in the Sensory Integration Special Interest Section or School System Special Interest Section of the American Occupational Therapy Association in eastern and midwestern United States. The valid return rate was 58% (292 respondents). The survey used Likert scale items to measure frequency of performance problems observed in children with PDD, performance areas addressed in intervention, perceived improvement in performance, and frequency of use of and competency in intervention approaches.

RESULTS

The respondents primarily worked in schools and reported that in the past 5 years they had served an increasing number of children with PDD. Most respondents provided direct services and appeared to use holistic approaches in which they addressed multiple performance domains. They applied sensory integration and environmental modification approaches most frequently and believed that they were most competent in using these approaches. Respondents who reported more frequent use of and more competence in sensory integration approaches perceived more improvement in children's sensory processing. Respondents who reported more frequent use of and more competence in child-centered play perceived more improvement in children's sensory integration and play skills.

Distance education and caregiver support groups: comparison of traditional and telephone groups

OBJECTIVE

To implement and evaluate the impact of telephone caregiver groups, compared with traditional face-to-face, on-site caregiver groups.

DESIGN

Quasi-experimental design comparing the two group types across time.

SETTING

An urban tertiary rehabilitation hospital with a brain injury program servicing a vast geographical area.

PARTICIPANTS

Caregivers of an adult person with a brain injury participated in either one of the 10 telephone groups (TGs) (N = 52 caregivers who completed a full set of research forms) or one of the 10 on-site groups (OGs) (N = 39 caregivers who completed a full set of research forms). The combined total from both groups was 91.

INTERVENTION

Caregivers who lived within 40 km of the facility were placed in one of the OGs, and all others were placed in one of the TGs. Both types of groups met weekly for 9 to 10 weeks and were led by either social work or psychology professionals. The TGs met using teleconference technology.

MAIN OUTCOME MEASURES

Profile of Moods States (POMS), Caregiver Burden Inventory (CBI), and the McMaster Model Family Assessment Devise (FAD), were administered 2 months before the first day of group, on the first day of group, on the last day of group, and 6 months after group. On the last day of group, a participant satisfaction survey was administered.

RESULTS

There were similar amounts of improvements for the outcomes from OGs and TGs. Rural caregivers had fewer difficulties on all measures at all measurement intervals. In both types of group, participants showed a statistically significant improvement in POMS scores and a trend toward improvement in FAD and CBI results. Participants of both group types rated their experience highly, although rural caregivers were somewhat more satisfied.

CONCLUSIONS

Telephone groups offer a method of providing support and education to rural caregivers that is as effective as traditional in-person OGs.

Clinical and inflammatory effects of dietary L-arginine in patients with intractable angina pectoris

We evaluated the effects of oral L-arginine on the clinical outcome and the inflammatory markers of patients with intractable angina pectoris. Our findings demonstrated a significant clinical improvement in 7 of 10 patients, which was associated with a significant decrease in cell adhesion molecule and proinflammatory cytokine levels. Dietary L-arginine may have clinical beneficial effects in patients with intractable angina pectoris, and may have anti-inflammatory properties.

Audio-computer interviewing to measure risk behaviour for HIV among injecting drug users: a quasi-randomised trial

BACKGROUND

We aimed to assess audio-computer-assisted self-interviewing (audio-CASI) as a method of reducing under-reporting of HIV risk behaviour among injecting drug users.

METHODS

Injecting drug users were interviewed at syringe-exchange programmes in four US cities. Potential respondents were randomly selected from participants in the syringe exchanges, with weekly alternate assignment to either traditional face-to-face interviews or audio-CASI. The questionnaire included items on sociodemographic characteristics, drug use, and HIV risk behaviours for 30 days preceding the interview. We calculated odds ratios for the difference in reporting of HIV risk behaviours between interview methods.

FINDINGS

757 respondents were interviewed face-to-face, and 724 were interviewed by audio-CASI. More respondents reported HIV risk behaviours and other sensitive behaviours in audio-CASI than in face-to-face interviews (odds ratios for reporting of rented or bought used injection equipment in audio-CASI vs face-to-face interview 2.1 [95% CI 1.4-3.3] p=0.001; for injection with borrowed used injection equipment 1.5 [1.1-2.2] p=0.02; for renting or selling used equipment 2.3 [1.3-4.0] p=0.003).

INTERPRETATION

Although validation of these self-reported behaviours was not possible, we propose that audio-CASI enables substantially more complete reporting of HIV risk behaviour. More complete reporting might increase understanding of the dynamics of HIV transmission and make the assessment of HIV-prevention efforts easier.

Nucleus taenia of the amygdala of birds: anatomical and functional studies in ring doves (Streptopelia risoria) and European starlings (Sturnus vulgaris)

Nucleus taenia (Tn) in birds is a discrete component of a loosely defined archistriatal structure, the posterior and medial archistriatum. By virtue of its hypothalamic projections, the posterior and medial archistriatum is thought to be an avian homolog of the amygdala in mammals. A recent fluorogold (FG) study of avian hippocampus revealed backfilled labels in nucleus Tn, suggesting that this nucleus may indeed be the homolog of mammalian amygdala. In the present study, we sought to characterize nucleus Tn in terms of its connections and function. We used the anterograde tracers Phaseolus vulgaris leucoagglutinin (PHAL) and biotinylated dextran amine (BDA) to map the efferent projections of Tn. The retrograde tracers FG and BDA were used to corroborate the efferent projections and to explore the pattern of afferent inputs to Tn. Finally, we explored the role of Tn in social behavior by observing behavioral changes associated with electrolytic lesions to Tn. The subjects of our studies were ring doves and European starlings, representing two avian orders. When a deposit of anterograde tracer was centered in Tn, it revealed projections to the hypothalamus, following the course of the hypothalamic-occipitomesencephalic tract previously reported in pigeons. The projections were bilateral in ring doves and ipsilateral in starlings. The BDA injections in the archistratum intermedium, lateral to Tn, did not yield the same projectional pattern. Together with corroborative data from FG retrograde experiments, these findings suggest that Tn is probably the primary origin of the hypothalamic projection. A robust projection to the hyperstriatal region was present along the lateral wall of the lateral ventricle, continuing into the anteroventral pole of the ventricle. Highly arborized terminal fields were found all along this pathway, notably in the medial parolfactory lobe (corresponding to the basal ganglia) and along the dorsal roof of the rostral hyperstriatum ventrale just ventral to the laminal frontalis superior (in ring doves) and the lamina frontalis suprema (in starlings). Projections to the hippocampal complex were mostly restricted to the parahippocampus. The FG data suggest the presence of afferent projections from the ovoidais shell and nucleus subrotundus region, the hippocampal complex in both species, and high vocal nucleus in starlings. Behavioral effects of Tn lesions suggest that nucleus taenia is involved in the control of social behavior through its influence on the affective state. Nucleus taenia thus exhibits many of the structural and functional features of the amygdaloid complex in mammals - that is, subcortical sensory inputs, hippocampal complex connections, and a functional role in adaptive patterns of social behavior.

Intrinsic myocardial function in hemorrhagic shock

Hemorrhage is a stress on the cardiovascular system that results in decreased loading of the heart but also decreased blood pressure and thus decreased perfusion pressure for tissue blood flow. The heart's response to hemorrhage is governed by both an increase in sympathetic nervous system activation of the heart and decreased preload and afterload for the heart. Whether the heart can maintain normal contractile function and reserves under conditions of prolonged hemorrhagic shock is not clear. To assess the effects of hemorrhagic shock of different lengths on intrinsic cardiac contractile function, guinea pigs were surgically prepared for the measurement of blood pressure, heart rate, and cardiac output and blood samples were taken for the measurement of metabolic indices of cardiovascular stress. Fifty percent of the animals' blood volume was removed and then animals were followed for 1, 2, or 3 h of hemorrhagic shock. Hearts were then removed for measurement of intrinsic contractile function. Hearts from animals exposed to 1 or 2 h of shock exhibited normal ventricular function although hearts removed after 3 h exhibited changes in ventricular function. Maintenance of normal cardiac function through at least 2 h of shock must represent adequate physiologic modulation of coronary blood flow to deliver adequate oxygen to match the myocardial oxygen demands under conditions of severe blood loss. This balance may be disrupted by 3 h of shock thus resulting in loss of contractile reserve.

First clinical experience with the premounted balloon-expandable serpentine stent: acute angiographic and intermediate-term clinical results

The beStent-Artist coronary stent is a newly developed, stainless steel coronary stent with a serpentine tubular design and terminal stent markers, premounted on a semicompliant balloon. During this pilot evaluation we aimed to test the acute clinical and angiographic results, short-term (30 days) and 6-month clinical results. A total of 57 stents were used to treat 43 lesions in 40 patients. Deployment strategy included predilatation, stent deployment, balloon repositioning to match the distal end of the balloon to the distal stent marker, and subsequent 12-14 atm postdilatation. There were two cases of stent dislodgment, but no procedural complications. In four cases, stent recrossing with another balloon was necessary. In two of these cases, distal dissections were observed and treated with another stent. The minimal lumen diameter (MLD) increased from 0.84+/0.52 mm at baseline to 2.7+/-0.62 mm at the end of the procedure (a corresponding decrease in diameter stenosis from 78.6 > 16.4 to 18.2+/-10.7%). The acute gain was 1.89+/-0.61mm. No adverse events occurred by 30 days. During six months, 7/40 (18.5%) of patients required target vessel revascularization due to in-stent restenosis. In summary, the premounted beStent-Artist can be delivered and deployed with favorable immediate results and high success rate with favorable long-term recurrent event rates.

High anti-cytomegalovirus (CMV) IgG antibody titer is associated with coronary artery disease and may predict post-coronary balloon angioplasty restenosis

Recent studies have demonstrated that cytomegalovirus (CMV) DNA was found in atherosclerotic coronary arteries in restenotic lesions, and prior infection with CMV could be a strong independent risk factor for restenosis after coronary atherectomy. We studied the correlation between anti-CMV antibody titer and coronary artery disease. Sixty-five patients (50 men and 15 women) with coronary artery disease were enrolled prospectively. All had symptomatic coronary artery disease with an angiographic documentation of a de novo single coronary lesion. All underwent balloon coronary angioplasty and were followed for 12 months with a thallium perfusion scan 3 months after angioplasty. Patients who had recurrent chest pain and/or a positive thallium scan had another coronary angiography. Blood samples were taken before angiography and 1 and 3 months later. Patients with high anti-CMV titer > or = 1:800 had a higher prevalence of coronary artery disease (p <0.001) than seropositive patients with a lower antibody titer (< or = 1:400); patients with high antibody titer (> or = 1:800) had a higher restenosis rate than seropositive patients with a low antibody titer (< or = 1:400) (p <0.05). High antibody titers against CMV (IgG) may be a strong marker for coronary artery disease, and might predict post-coronary angioplasty restenosis. These findings support the infectious theory of atherosclerosis (especially with prior CMV infection), and also suggest that a chronic immunologic response has a role in atherosclerosis and restenosis.

The use of videotaped information in cancer genetic counselling: a randomized evaluation study

A video of introductory information about inherited susceptibility to breast cancer was made in consultation with clinicians in four Scottish cancer family clinics. One hundred and twenty-eight women, newly referred for breast cancer risk counselling were randomized to receive the video before (n = 66) or after (n = 62) counselling. Data were collected before randomization at clinic and by postal follow-up at 1 month. The Video Before group had shorter consultations with the breast surgeon (mean = 11.8 min+/-5.4 vs 14.6+/-7.2 for the Video After group). There was no difference between the groups in the accuracy of their risk estimate after counselling, although the Video Before group scored higher for self-reported (Z= 3.65, d.f. = 1, P < 0.01) and objectively assessed understanding (Z= 2.91, d.f. = 1, P < 0.01). At 1 month follow-up, the Video Before group were less likely to underestimate their risk estimate (38% vs 18%; chi2 = 4.62, d.f. = 1, P< 0.05), but there was then no difference between the groups in subjective or objective understanding. Use of the video was not associated with increased distress (GHQ, Spielberger State Anxiety) and was associated with greater satisfaction with the information given at the clinic. This study supports the value of videotape as a method of giving information to prepare women for breast cancer risk counselling. Observations of misunderstandings and distress emphasize the video should be seen as an aid to, not a substitute, for communications at the clinic.

Autoimmune and inflammatory responses may have an additive effect in postpercutaneous transluminal coronary angioplasty restenosis

Patients who had an increase in their serum amyloid type A level of > 100% in the first 24 hours after percutaneous transluminal coronary angioplasty (PTCA) and also developed a positive antibody result (antinuclear factor or anticardiolipin), had a relative risk of 10.6 for developing restenosis in the first year after PTCA.

Role of cytokines in heart failure

Heart failure is a complex neurohumoral and inflammatory syndrome. Studies have shown that proinflammatory cytokines (interleukin-1, interleukin-2, interleukin-6, and tumor necrosis factor) are involved in cardiac depression and in the complex syndrome of heart failure. Understanding the involvement of these cytokines may enable us to reverse cardiac depression and heart failure with the use of monoclonal antibodies directed against specific cytokines that may block the downhill progression of heart failure.

Treatment of Felty's syndrome with the haemopoietic growth factor granulocyte colony-stimulating factor (G-CSF)

Felty's syndrome (FS) (rheumatoid arthritis with neutropenia and splenomegaly) has a poor prognosis, largely because of the high risk of severe infection. Granulocyte colony-stimulating factor (G-CSF) is an emerging treatment for chronic neutropenia. We prospectively monitored its use in eight patients with recurrent infections or who required joint surgery. Significant side-effects were documented in five, including nausea, malaise, generalized joint pains, and in one patient, a vasculitic skin rash. In two patients treatment had to be stopped, and in these cases G-CSF had been started at full vial dosage (300 micrograms/ml filgrastim or 263 micrograms/ml lenograstim) alternate days or daily. G-CSF treatment was continued in three patients by restarting at reduced dose, and changing the proprietary formulation. G-CSF raised the neutrophil count, reduced severe infection, and allowed surgery to be performed. A combined clinical and laboratory index suggested that long-term treatment (up to 3.5 years) did not exacerbate the arthritis. Once on established treatment, it may be possible to use smaller weekly doses of G-CSF to maintain the same clinical benefit. One of the three patients whose FS was associated with a large granular T-cell lymphocytosis showed a reduction in this subset of lymphocytes during G-CSF treatment.

Kinetics of DNA polymerase I (Klenow fragment exo-) activity on damaged DNA templates: effect of proximal and distal template damage on DNA synthesis

Mutagenic DNA adducts have been analyzed with respect to the rate of nucleotide insertion opposite the modified base, extension from that "mispair", and nucleotide insertion preference. To complement and extend these studies we have investigated the long-range effects of DNA adducts on DNA polymerase activity. To address this question, primer extension reactions were performed using DNA polymerase I, Klenow fragment exo-. Templates containing 7,8-dihydro-8-oxoguanine, dG-C8-aminofluorene, dG-C8-(acetylamino)fluorene, and the model abasic site, tetrahydrofuran, were used for these studies, and the steady-state kinetics of correct nucleotide insertion were determined at positions (-2), (-1), (+1), (+2), (+3), and (+5) with respect to the template lesion. The kinetics of primer extension by Klenow fragment exo- at template positions 3' to the lesion showed only a small inhibitory effect, <3-fold, even for the strongly blocking lesion, dG-C8-(acetylamino)fluorene, indicating that Klenow fragment exo- activity is not greatly affected by lesions in the single-stranded portion of the template-primer. In contrast, a dramatic decrease in the frequency of primer extension was observed at template sites 5' to the site of adduction. Inhibition of polymerase activity decreased as the distance from the lesion increased; however, a relatively large effect was seen at the (+2) and (+3) positions for dG-C8-(acetylamino)fluorene and tetrahydrofuran. For these blocking lesions, the effect on extension 5 bases from the lesion was greatly reduced. We conclude from these studies that DNA damage at positions remote from the site of the lesion affects DNA polymerase function.

Femoral artery pseudoaneurysm: Doppler sonographic features predictive for spontaneous thrombosis

PURPOSE

The objective of this prospective study was to evaluate whether Doppler imaging characteristics can be used to predict spontaneous thrombosis of femoral artery pseudoaneurysms (PAs).

METHODS

Eleven post-cardiac catheterization PAs were monitored with color Doppler sonography. Total volume of the lesion, volume filled with free-flowing blood, length and width of the neck of the PA, and its anatomic position were evaluated.

RESULTS

All of the PAs in our series underwent spontaneous thrombosis. PAs with necks 0.9 cm or longer underwent spontaneous thrombosis in 9.8 days on average, while PAs with necks shorter than 0.9 cm required an average of 52 days to thrombose.

CONCLUSIONS

PAs with longer neck lengths are more likely to thrombose in a shorter period than are those with shorter necks. It may thus be worthwhile to await spontaneous resolution when the aneurysmal neck length is 0.9 cm or more.