Clinical and echocardiographic characteristics of cardioembolic stroke.

BACKGROUND AND PURPOSE: Ischaemic stroke frequently has a cardioembolic (CE) source. Clinical and echocardiographic parameters associated with CE stroke were evaluated. METHODS: In all, 93 consecutive ischaemic stroke patients who underwent a transthoracic echocardiogram were retrospectively analysed; strokes were classified by TOAST (Trial of Org 10172 in Acute Stroke Treatment) criteria. Echocardiographic parameters related to CE stroke, including left atrial volumes and function, were compared to 73 healthy controls. RESULTS: Of 93 patients (mean age 66.1 years, 56% male), nine (10%) had large artery atherosclerosis, 38 (41%) CE stroke, two (2%) small vessel disease, two (2%) other and 42 (45%) undetermined aetiology. Left atrial (LA) maximum volumes (LAVImax ) and minimum volumes (LAVImin ) were larger in the CE group than the non-CE group (45 vs. 32 ml/m2 , 32 vs. 13 ml/m2 , respectively, P < 0.001), whilst LA function indices including LA emptying fraction and LA function index (LAFI) were lower in the CE group (34% vs. 55%, and 0.12 vs. 0.35, respectively, P < 0.001). Adjusting for clinical characteristics, LAFI ≤0.3 was an independent predictor of CE stroke (adjusted odds ratio 5.3, P = 0.001). Additionally, LAVImax and LAVImin were larger (61 vs. 44 and 32 vs. 24 ml/m2 respectively, P < 0.01) and LAFI significantly lower (0.34 vs. 0.52, P < 0.001) in the undetermined aetiology group versus healthy controls. CONCLUSIONS: Left atrial enlargement with reduced LA function was associated with CE stroke and LAFI was the best independent predictor. LA parameters were also altered in the undetermined aetiology group, suggesting an underlying LA myopathy in this subset.

Evaluation of a peer education program on student leaders' energy balance-related behaviors.

BACKGROUND: Few studies have reported energy balance-related behavior (EBRB) change for peer leaders delivering health promotion programs to younger students in secondary schools. Our study assessed the impact of the Students As LifeStyle Activists (SALSA) program on SALSA peer leaders' EBRBs, and their intentions regarding these behaviors. METHODS: We used a pre-post study design to assess changes in EBRBs and intentions of Year 10 secondary school students (15-16 year olds) who volunteered to be peer leaders to deliver the SALSA program to Year 8 students (13-14 year olds). This research is part of a larger study conducted during 2014 and 2015 in 23 secondary schools in Sydney, Australia. We used an online questionnaire before and after program participation to assess Year 10 peer leaders' fruit and vegetable intake, daily breakfast eating, sugar sweetened beverage (SSB) intake, moderate-to-vigorous physical activity (MVPA) participation and school-day recreational screen time behaviors and intentions regarding these EBRBs. Generalized estimating equations with a robust variance structure and exchangeable correlation structure were used to estimate the individual-level summary statistics and their 95% CIs, adjusted for clustering. We further assessed the effect of covariates on EBRB changes. RESULTS: There were significant increases in the proportion of Year 10 peer leaders (n = 415) who reported eating ≥2 serves fruit/day fruit from 54 to 63% (P < 0.01); eating ≥5 serves vegetables/day from 8 to 12% (P < 0.01); and drinking <1 cup/day of SSBs from 56 to 62% (P < 0.01). Change in ≥60 min MVPA participation/day depended on gender (P < 0.01): Boys increased 14% while girls decreased -2%. Changes in eating breakfast daily also depended on gender (P < 0.004): Boys increased 13% while girls decreased -0.4%. The change in peer leaders recreational screen time differed by socio-economic status (P < 0.05): above average communities decreased by -2.9% while below average communities increased 6.0%. Significant shifts were seen in peer leaders' intentions, except MVPA which remained stable. CONCLUSIONS: The SALSA program had a positive impact on peer leaders' EBRBs, with gender and socio-economic status moderating some outcomes. TRIAL REGISTRATION: ACTRN12617000712303 retrospectively registered.

Epilepsy in patients with primary brain tumors: The impact on mood, cognition, and HRQOL.

BACKGROUND: A primary brain tumor (PBT) is often a fatal disease of the nervous system and has a serious impact on health-related quality of life (HRQOL). Presence of epilepsy and adverse reactions from tumor and epilepsy treatments may cause additional decline in HRQOL. OBJECTIVES: We aimed to study the impact of epileptic seizures on cognition, mood, and HRQOL in patients with brain tumor-related epilepsy. MATERIALS AND METHOD: Patients were grouped on an ordinal scale according to epilepsy burden from none to severe based on the presence of epileptic seizures and seizure frequency: L1, no epilepsy; L2, with epilepsy, seizure-free in the last 6 months with antiepileptic drugs; and L3, with epilepsy, at least one seizure in the last 6 months with AEDs. Health-related quality of life was measured by Functional Assessment of Cancer Therapy-Brain (FACT-Br) and Quality of Life in Epilepsy-31 (QOLIE-31) tools, cognition by the Montreal Cognitive Assessment (MoCA) tool and Frontal Assessment Battery (FAB), mood by the Hospital Anxiety and Depression Scale (HADS), activities of daily living (ADLs) by the Barthel Index (BI), and performance status by the Karnofsky Performance Status (KPS) scale in patients with primary brain tumors at least one month following neurosurgery with or without radiotherapy and chemotherapy. RESULTS: Eighty-one patients with a diagnosis of primary brain tumors were recruited. Sixty-eight percent of patients were diagnosed with primary brain tumor-related epilepsy, 50.61% patients had cognitive impairment, 33% had abnormal scores in the anxiety scale, and 34% had abnormal scores in the depression scale. There were no statistically significant differences in these scores among L1, L2, and L3 groups. There were statistically significant differences in duration of disease and KPS and BI scores between L1 and L3 groups. The L3 group has significantly longer duration of disease and scored low in both the BI and KPS scale when compared to the L1 group. All patients with primary brain tumors scored significantly low in FACT-Br 'physical well-being' (PWB) and 'emotional well-being' (EWB) and high in 'social well-being' (SWB) when compared to healthy controls. When scores of each group were individually compared to healthy controls, the L3 group showed the lowest scores in PWB, EWB, and 'functional well-being'. In SWB, L1 and L2 groups showed statistically significantly high scores when compared to normative data. The QOLIE-31 applied to groups with epilepsy showed statistically significantly lower scores in the L3 group when compared to the L2 group in 'cognitive' and 'social functioning' domains. On multivariate analysis, both poor performance status and frequency of seizures were found to be independent risk factors for poor HRQOL when FACT-Br mean scores were compared. Level of seizures was found to be an independent risk factor for poor HRQOL when QOLIE-31 scores were compared between L2 and L3 groups. DISCUSSION: Presence of brain tumors could be attributed to cognitive impairment irrespective of the presence of epilepsy in our cohort. High seizure burden is an independent risk factor for poor HRQOL in patients with primary brain tumors. The QOLIE-31 is a more sensitive tool than the FACT-Br because of the presence of a seizure-related questionnaire.

An investigation of risk factors associated with tooth surface loss: a pilot study.

Few prospective studies have investigated risk factors associated with severe tooth surface loss. This case-control study assessed the possible association between medical history, diet, psychological profile and salivary pH and flow [Delongis 1982, Johansson 1993] with the incidence of severe tooth surface loss. A total of 80 subjects (40 cases and 40 age- and gender-matched controls) aged 25-85 years were recruited. Cases were subjects with severe tooth surface loss, and controls with mild tooth surface loss. Conditional logistic regression analysis estimated the odds of severe tooth surface loss to be 15·4 times higher for those with cardiovascular disease and 16 times for gastrointestinal disturbances. Most domains of the psychological profile were associated with elevated risk of severe tooth surface loss, particularly the effects of finance and health. Recreational drug use and prescription medications were also associated with severe tooth surface loss. There was no association between salivary flow and severe tooth surface loss. Although not statistically significant, the pH was slightly lower in the severe tooth surface loss group.

Factors that predict bleeding following endoscopic mucosal resection of large colonic lesions.

BACKGROUND AND STUDY AIMS: Endoscopic mucosal resection (EMR) for large colonic laterally spreading tumors (LSTs) is a safe, efficacious, and cost-effective treatment. The most common serious complication is delayed bleeding, which reduces these advantages, but consensus guidelines for large-polyp EMR do not exist. PATIENTS AND METHODS: Data from two large prospective intention-to-treat studies of EMR for colonic LSTs 20 mm or greater in size were analyzed. Data collection was comprehensive, and included patient and lesion characteristics. EMR technique and cessation of anticoagulant and antiplatelet therapy was standardized. Clinically significant delayed bleeding was defined as that requiring hospital admission. RESULTS: EMR was performed on 302 lesions in 288 patients. There was clinically significant delayed bleeding in 21 cases (7 %). Ten underwent colonoscopy. One required angiography. One required surgery after perforation following hemostatic clip placement. There were no deaths. Risk factors for bleeding on multivariate analysis were right colon location [adjusted odds ratio (OR) 4.4, P = 0.01], use of aspirin (OR 6.3, P = 0.005), and age (OR per decade of age 1.70). All bleeds occurred before aspirin was restarted. Patient characteristics, including ASA grade and co-morbidity type, were not predictive. Despite requiring more complex EMR, larger lesion size ( P = 0.2), multiple excisions rather than en bloc resection ( P = 0.1), polyp morphology ( P = 0.2), and previous attempts ( P = 0.5), were not associated with increased risk. CONCLUSIONS: Proximal lesion location is a highly significant risk for clinically significant delayed bleeding following colonic EMR, and this knowledge could form the basis of a targeted therapeutic trial. Recent aspirin use also increases bleeding risk--specific consensus guidelines in this area are required for colonic EMR.

Complete Barrett's excision by stepwise endoscopic resection in short-segment disease: long term outcomes and predictors of stricture.

BACKGROUND AND STUDY AIMS: Complete Barrett's excision (CBE) of short-segment Barrett's high grade dysplasia (HGD) and early esophageal adenocarcinoma by stepwise endoscopic resection is a precise staging tool, detects covert synchronous disease, and may produce a sustained treatment response. Esophageal stricture is the most commonly reported complication of CBE although risk factors have not yet been clearly defined. PATIENTS AND METHODS: Data were recorded prospectively on patients with limited co-morbidity and age ≤ 80 years undergoing CBE for histologically proven HGD or esophageal adenocarcinoma within ≤ C3M5 segments. Endoscopic resection was performed by standardized protocol every 6 - 8 weeks until CBE was achieved. Esophageal dilation was performed when patients reported dysphagia. Dysphagia scores were recorded at scheduled endoscopic surveillance or by telephone interview. RESULTS: By intention-to-treat analysis, complete eradication of neoplasia and intestinal metaplasia was achieved in 95 % and 82 %, respectively, in 77 patients undergoing a median of 2 resection sessions (interquartile range [IQR] 1 - 3). Esophageal dilation was required in 33 % (median 3 dilations, IQR 1 - 3.5) at median follow-up of 20 months (IQR 6 - 40). Independent risk factors for dilation requirement were the number of mucosal resections at the index procedure (odds ratio [OR] 1.3 per resection, 95 % confidence interval [CI] 1.0 - 1.9; P = 0.043) and maximal extent of the Barrett's segment (OR 2.2 per cm, 95 %CI 1.2 - 3.9; P = 0.009). CONCLUSIONS: Although CBE is highly effective in the treatment of Barrett's HGD and esophageal adenocarcinoma, the risk of post-CBE dysphagia increases with the maximal extent of the Barrett's segment and the number of mucosal resections at the index procedure. These data could be used to inform treatment decisions and identify those patients who may benefit from prophylactic therapies such as dilation.

CD45-null transgenic mice reveal a positive regulatory role for CD45 in early thymocyte development, in the selection of CD4+CD8+ thymocytes, and B cell maturation.

The CD45 transmembrane glycoprotein has been shown to be a protein phosphotyrosine phosphatase and to be important in signal transduction in T and B lymphocytes. We have employed gene targeting to create a strain of transgenic mice that completely lacks expression of all isoforms of CD45. The spleens from CD45-null mice contain approximately twice the number of B cells and one fifth the number of T cells found in normal controls. The increase in B cell numbers is due to the specific expansion of two B cell subpopulations that express high levels of immunoglobulin (IgM) staining. T cell development is significantly inhibited in CD45-null animals at two distinct stages. The efficiency of the development of CD4-CD8- thymocytes into CD4+ CD8+ thymocytes is reduced by twofold, subsequently the frequency of successful maturation of the double positive population into mature, single positive thymocytes is reduced by a further four- to fivefold. In addition, we demonstrate that CD45-null thymocytes are severely impaired in their apoptotic response to cross-linking signals via T cell receptor (TCR) in fetal thymic organ culture. In contrast, apoptosis can be induced normally in CD45-null thymocytes by non-TCR-mediated signals. Since both positive and negative selection require signals through the TCR complex, these findings suggest that CD45 is an important regulator of signal transduction via the TCR complex at multiple stages of T cell development. CD45 is absolutely required for the transmission of mitogenic signals via IgM and IgD. By contrast, CD45-null B cells proliferate as well as wild-type cells to CD40-mediated signals. The proliferation of B cells in response to CD38 cross-linking is significantly reduced but not abolished by the CD45-null mutation. We conclude that CD45 is not required at any stage during the generation of mature peripheral B cells, however its loss reveals a previously unrecognized role for CD45 in the regulation of certain subpopulations of B cells.

Methotrexate: long-term safety and efficacy in an Australian consultant rheumatology practice.

BACKGROUND: The aim of this study was to evaluate the rate and cause of methotrexate (MTX) termination in clinical practice, describe the types of toxicities noted, assess the incidence of achieving remission in rheumatoid arthritis (RA) patients and review the appropriateness of current clinical guidelines for monitoring MTX treatment. METHODS: A retrospective, case review of patients seen in a private rheumatology practice attached to a major Sydney Teaching Hospital was undertaken over an 18-year period. The primary outcome was time to cessation of MTX. RESULTS: Seven hundred and ninety patients satisfied the inclusion criteria. MTX was terminated in 272 patients (34.4%). Toxicity-related discontinuation occurred in 93 patients (11.8%) and due to non-adverse reactions in 179 patients. The median duration of therapy in these two groups was 2.0 and 2.9 years, respectively. There was no difference in the average maximum weekly dose of MTX. Of patients with RA, 47.5% were in remission at last follow up. Cox proportional hazards analyses showed that those of the female sex remained on treatment significantly longer than the male sex (hazard ratio (HR) 0.73, 95% confidence interval (CI) 0.57-0.96; P = 0.014); patients with RA remained on treatment significantly longer than patients with seronegative arthritis (HR 0.56, 95%CI 0.42-0.74; P < 0.001). Being of the male sex aged more than 60 years and having a non-RA diagnosis predisposed to stopping MTX earlier. CONCLUSION: MTX is a safe and effective medication. Notable remission rates are achievable in patients with RA with current conventional treatment protocols. MTX has a low toxicity profile and this study stresses the need to re-evaluate and revise the current monitoring guidelines.

Familial scleroderma: nature, nurture or both?

BACKGROUND: The aim of the study was to investigate: (i) familial scleroderma (FS) risk factors, (ii) subtype concordance and (iii) relationship between dates (DSO) and ages (ASO) at scleroderma onset. METHODS: Forty-seven cases (23 families; 25 FS pairs) were identified. Scleroderma disease onset was defined by (i) Raynaud's onset, (ii) first symptom onset (1SxO), (iii) second symptom onset (2SxO) and (iv) scleroderma diagnosis (SDx). RESULTS: Female : male and limited : diffuse (L : D) ratios were 8.4:1 and 3.3:1. The Raynaud's onset - SDx interval was longer in limited disease (L : D = 14.6:3.1 years; P = 0.01). Raynaud's first occurred in 36% women > or =50 years. The median differences in ASO between affected family members were 10-12 years. Disease subtype concordance exceeded discordance (16:9 clusters; (P = 0.32) 16:7 families; (P = 0.17)). The observed/expected LL : LD : DD ratios were 14: 8:1/11:7:1 (P = 0.66). FS affected 34% (95% confidence interval 19-50) sister-sister and 44% (95% confidence interval 27-75) mother-daughter pairs. The second family member's SDx was made at the same (9%) or a younger age (80%) than the first family member. In 14 LL disease families ASO was closer between sisters than mothers-daughters (P = 0.07). There was a trend towards closer ages - than dates - at Raynaud's and 1SxO in scleroderma-affected family members (P = 0.054) and closer dates - than ages - at 2SxO (P = 0.02) and SDx. CONCLUSION: FS showed female predominance, relatively late onset Raynaud's, subtype ratios similar to idiopathic scleroderma and earlier SDx in younger family members. Familial L scleroderma has a longer prediagnostic latency than familial D scleroderma. FS is likely under-ascertained. In LL scleroderma, Raynaud's/1SxO is possibly more genetically determined and 2SxO/SDx more environmentally determined.

Comparison and validation of three measures of quality of life in patients with pulmonary hypertension.

BACKGROUND: Pulmonary hypertension, when advanced, markedly limits exercise capacity, activities of daily living and quality of life (QoL). No measure of QoL has yet been validated for the assessment of pulmonary hypertension. The aim of the study was to compare the validity of the Minnesota Living with Heart Failure (MLwHF) questionnaire, the Short Form-36 (SF-36) questionnaire and the Australian Quality of Life (AQoL) measure for assessing pulmonary hypertension treatment. METHODS: Eighty-three patients were enrolled in three studies of pulmonary hypertension treatment (treprostinil, bosentan and sildenafil). They were assessed at baseline and 3 months with the MLwHF questionnaire. Treprostinil and bosentan groups also had 6 and 12 months' data. Twenty-one patients in the sildenafil trial completed concurrently, the SF-36 and AQoL measures at baseline and 3 months. QoL scores were correlated with the 6-min walk test distance, New York Heart Association functional class and right heart catheter-derived haemodynamic parameters of the disease for all matching time points and for changes in scores and clinical measurements over time. RESULTS: The MLwHF and SF-36 scores correlated well with the 6-min walk test distance and New York Heart Association functional class, but did not correlate with haemodynamic measurements. MLwHF and SF-36 scores also correlated with the rate of change of the 6-min walk test distance and New York Heart Association functional class over time. CONCLUSION: The MLwHF questionnaire and SF-36 are useful tools for the assessment of QoL in pulmonary hypertension and may be useful in the ongoing evaluation of QoL in the treatment and study of pulmonary hypertension.

Volumetric analysis of a specific language region - the planum temporale.

Planum temporale volumes were determined for 42 control children (ages 4.2-15.7 years) using magnetic resonance imaging. The mean left planum temporale volume was 2729 mm3 (SD = 567) and the mean right planum temporale volume was 2758 mm3 (SD = 546). No significant hemispheric asymmetry was demonstrated. Analysis of co-variance (ANCOVA) showed that the absolute and proportional planum temporale volumes were not significantly associated with age or gender. We also demonstrated a reproducible method for planum temporale volume measurement by acquiring images in the coronal plane and then visualising the sagittal plane to improve accuracy for the posterior border.

Relative expression of progesterone receptors A and B in endometrioid cancers of the endometrium.

The nuclear receptor for the female hormone progesterone (PR) is widely expressed in uterine cancer. PR is expressed as two proteins (PRA and PRB) with different functions, and in vitro evidence reveals PRA to inhibit PRB function, so the cellular ratio of PRA:PRB is likely to be an important determinant of progesterone action. The relative expression of PRA and B and their involvement in the pathogenesis of endometrial cancer is not known. The aims of this study were to determine PRA and B expression by dual immunofluorescent histochemistry in endometrial adenocarcinomas compared with expression in normal and hyperplastic glands, and to correlate expression in tumors with clinical features including grade. Significantly lower PR levels were found in tumors compared with normal glands and areas of complex atypical hyperplasia within the same specimen. The normal glands expressed both of the isoforms at similar levels, whereas there was increased predominance of one isoform in hyperplastic areas and in tumors, which suggested that the loss of coordinated expression of PR isoforms was an early event in tumor progression. The majority of tumors [27 (58%) of 46] expressed only one PR isoform, and the proportion expressing either PRA or B was the same [14 (30%) of 46, and 13 (28%) of 46, respectively]. One-half of all tumors ([23 (50%) of 46] expressed either PRA only or a predominance of PRA, and a few tumors [10 (22%) of 46] expressed comparable levels of PRA and B. Similar levels of PRA and B were noted only in FIGO grade 1 tumors, whereas higher grades (2 and 3) were associated with a predominance of one isoform. In summary, expression of only one PR isoform was common in endometrial cancers, which indicates that the decreased PR levels observed in these cancers arise from the loss of one PR isoform. Expression of a single PR isoform was associated with higher clinical grade, which suggests a relationship between the loss of PR isoform expression and features of poorer prognosis. Disruption of relative PR isoform expression was observed in complex atypical hyperplasia, which suggests that early alterations in the ratio of PRA:PRB may precede and/or be implicated in the development of endometrial adenocarcinoma. Alterations in the ratio of PR isoform expression are likely to cause disordered regulation of target genes, resulting in altered progestin action in the uterus, and this may be involved in the pathogenesis of endometrial cancer.

Geographic heterogeneity of cellular characteristics of acute myeloid leukemia: a comparative study of Australian and Japanese adult cases.

We assessed a large number of adults (368 from Australia and 494 from Japan) with de novo acute myeloid leukemia (AML) to define the biological differences between the two populations. In this study, AML was classified using the French-American-British (FAB) criteria into seven groups (M1-M7). M2 was more common in Japan than in Australia, whereas M4 occurred more frequently in Australia than in Japan. Other FAB subtypes were evenly distributed. Cytogenetically, Japanese M2 displayed a higher frequency of t(8;21) than Australian (33.1% vs 15.3%, P < 0.05). The t(15;17), inv/del(16), 11q23 aberrations and 5/7/8 abnormalities were seen at similar frequencies. Immunophenotypically, Japanese M4/M5 more frequently displayed CD13 and CD14 than Australian, whereas the stem cell markers, CD34 and HLA-DR were observed at a relatively higher rate in Australian M3 than in Japanese M3. The B cell antigen, CD19 was more frequently seen in Japanese M2 than in Australian M2, but found more often in Australian M5 than in Japanese M5. In both populations, a close relationship was observed between the expression of CD19 and t(8;21). These findings suggest different biological characteristics of AML between the two populations, the main differences being generated by a higher frequency of t(8;21) chromosomal abnormality in Japanese AML. Leukemia(2000) 14, 163-168.

Red clover isoflavones enriched with formononetin lower serum LDL cholesterol-a randomized, double-blind, placebo-controlled study.

BACKGROUND: Although postmenopausal combined hormone replacement therapy reduces the risk of hip fracture, long-term use may be associated with an increased risk of breast cancer, and in women more than 10 years after menopause it is associated with an increased risk of cardiovascular disease. Isoflavones, because of preferential binding to estrogen receptor beta, may retain the beneficial effects on bone but lessen the adverse effects on the breast. OBJECTIVE: The objective of this study was to study the effects of an isoflavone obtained from red clover (Rimostil) on bone mineral density, and on low-density lipoprotein (LDL) cholesterol. DESIGN: In a double-blind, randomized, placebo-controlled trial, 50 mg of Rimostil was given to women who were menopausal for at least 1 year. Bone mineral density of the spine, femoral neck and forearm and serum LDL cholesterol were measured at baseline and at 6-month intervals. The duration of follow-up was 2 years. RESULTS: There was no beneficial effect of Rimostil on bone density at any site. There was a 12% fall in serum LDL cholesterol in the Rimostil-treated arm, which was significantly greater than the 2% drop seen in the control arm (P=0.005).

Rapid, highly discriminatory binary genotyping to demonstrate methicillin-resistant Staphylococcus aureus transmission in a tertiary care intensive care unit.

OBJECTIVES: No previous studies of methicillin-resistant Staphylococcus aureus (MRSA) epidemiology in adult intensive care units (ICUs) have assessed the utility of rapid, highly discriminatory strain typing in the investigation of transmission events. DESIGN: Observational. SETTING: A 22-bed medical-surgical adult ICU. Patients Those admissions MRSA-positive on initial screening and all admissions <48 hours in duration were excluded, leaving a cohort of 653 patients (median age, 61 years; APACHE-II, 19). METHODS: We conducted this study of MRSA transmission over 1 year (August 1, 2011 to July 31, 2012) using a multiplex PCR-based reverse line blot (mPCR/RLB) assay to genotype isolates from surveillance swabs obtained at admission and twice weekly during ICU stays. MRSA prevalence and incidence rates were calculated and transmission events were identified using strain matching. Colonization pressure was calculated daily by summation of all MRSA cases. RESULTS: Of 1,030 admissions to ICU during the study period, 349 patients were excluded. MRSA acquisition occurred during 31 of 681 (4.6%) remaining admissions; 19 of 31(61%) acquisitions were genotype-confirmed, including 7 (37%) due to the most commonly transmitted strain. Moving averages of MRSA patient numbers on the days prior to a documented event were used in a Poisson regression model. A significant association was found between transmission and colonization pressure when the average absolute colonization pressure on the previous day was ≥3 (χ2=7.41, P=0.01). CONCLUSIONS: mPCR/RLB characterizes MRSA isolates within a clinically useful time frame for identification of single-source clusters within the ICU. High MRSA colonization pressure (≥3 MRSA-positive patients) on a given day is associated with an increased likelihood of a transmission event.

Renal graft thrombosis. A survey of 134 consecutive cases.

Despite overall improved graft survival, renal graft thrombosis (RGT) remains an important cause of graft loss. Of 6153 consecutive renal transplants (RTx), 134 index cases of graft loss from RGT were reported to the Australian and New Zealand Dialysis and Transplant Registry between 1980 and 1992. Two groups were selected for comparison: (1) institutional controls (n = 127), the previous RTx at the same institution as each index case; and (2) graft controls (n = 107), the contralateral cadaveric donor kidney of each index case. RGT cases that coincidentally occurred in control groups were deleted from those groups (6 of institutional controls, 2 of graft controls). RGT within the first 30 days after RTx occurred in 1.9% of all RTx and was constant from 1980 to 1992. In contrast, RGT caused an increasing proportion of early (within 30 days of RTx) graft losses (P = 0.01). The cumulative occurrence of RGT in those who thrombose was 62.6%, 83.7%, 90.2%, and 93.5% at 2, 7, 14, and 30 days after RTx, respectively. By comparison, with the control groups, no association with RGT was demonstrated for recipient age or sex, primary renal disease, type of dialysis, treatment with CsA, degree of HLA mismatch, panel reactive antibody levels, perfusion solution and perfusion technique, or immunosuppressive therapy. There was a significantly increased incidence of RGT with both extremes of donor age, female donors, and prolonged total ischemic time.

Cytomegalovirus and human herpesvirus 6 both cause viral disease after renal transplantation.

BACKGROUND: Systemic viral disease after renal transplantation, especially after treatment with OKT3 or antithymocyte globulin, has usually been attributed to cytomegalovirus (CMV) infection. Identification of human herpesvirus 6 (HHV6) has raised the possibility that infection or reactivation of this virus may also occur in the same setting. METHODS: We thus examined the incidence of CMV and HHV6 infection in a prospective blinded consecutive series of 30 renal and renal/pancreas transplant patients, 22 of whom received OKT3, antithymocyte globulin, or both. RESULTS: Clinical diagnosis of a viral syndrome was made in 15 patients. Three patients with only HHV6 DNA in urine or serum had fever and abnormal liver function but not neutropenia. All five CMV-seronegative patients who received positive kidneys developed moderate to severe disease with fever and neutropenia but also had HHV6 DNA in urine or serum. Seven CMV-seropositive patients developed disease, mostly after OKT3/antithymocyte globulin, but six shed both CMV and HHV6 in urine or serum. The simultaneous detection of both HHV6 and CMV DNA in either urine or serum was the strongest predictor of disease (and also the severity of disease), with an odds ratio of 99.0 (95% confidence intervals 5.4-1814, P<0.002). CONCLUSION: Most systemic viral disease after renal transplantation may be due to either coinfection or reactivation of CMV and HHV6 together. A wider understanding of risk factors for severe viral disease in this setting may come from testing for both viruses in all donors and patients in both clinical practice and clinical trials.

Defective depletion of CD45-null thymocytes by the Staphylococcus aureus enterotoxin B superantigen.

The development of a normal T-cell repertoire is critically dependent on the negative and positive selection events which occur at the CD4+CD8+ (double positive, DP) stage of thymic development. Depending on the avidity of the T-cell antigen receptor (TCR) for peptides presented within the thymus, DP thymocytes are either positively selected for maturation to CD4+/CD8+ single positive cells or are depleted by apoptosis. The addition of superantigen to thymocytes within foetal thymic organ culture (FTOC) mimics the negative selection signal of potentially autoreactive thymocytes and induces the responding population of thymocytes to apoptose. Here we present evidence that the transmembrane phosphotyrosine phosphatase CD45 critically regulates TCR-induced signals in thymic differentiation and present data to show defective depletion of CD45-null transgenic TCR-Vbeta8 DP thymocytes in FTOC by the Staphylococcus aureus Enterotoxin B (SEB) superantigen.

Does sotalol have reverse-use dependence during tachyarrhythmias?

This study assessed the effect of intravenous sotalol on right ventricular effective refractory period at right ventricular pacing rates of 600 and 300 ms cycle length at 3, 6, 9, and approximately 30 minutes after the dose of sotalol. Similar percent increases occurred in the ventricular effective period at the 2 heart rates at all tested times (p >0.2 in each case), and it was concluded that there is no evidence for reverse-use dependence of intravenous sotalol in its effects on right ventricular refractoriness over this range of heart rates.

Dimensions of the human posterior septal space and coronary sinus.

Accurate anatomic localization of accessory pathways during preoperative electrophysiologic study and during operative mapping depends on a knowledge of the dimensions of the posterior septal space and the left free wall. These dimensions were therefore studied in 48 human cadaver hearts. Mean distance from the coronary sinus orifice to the left margin of the posterior septal space was 2.3 +/- 0.4 cm and mean length of the left free wall was 5.0 +/- 1.0 cm. The posterior septal space at the level of the valve anuli extended a mean of 3.4 +/- 0.5 cm around the epicardium. The width of the posterior septum measured in the coronary sinus was related to heart weight and a combination of body weight and patient age (p less than 0.05). The probability of an accessory pathway being located in the left free wall or the posterior septum during catheter mapping was calculated for various distances from the coronary sinus orifice for adults of different ages and body weights. In adults, accessory pathways located in the proximal 1.5 cm of the coronary sinus are almost always in the posterior septum. Those located between 1.5 and 3 cm from the coronary sinus orifice may be in either the left free wall or the posterior septum, and those located greater than 3 cm from the coronary sinus orifice are almost invariably in the left free wall.