The safe use of metformin in heart failure patients both with and without T2DM: a cross-sectional and longitudinal study

AIMS

This study investigated the safe use of metformin in patients with (1) type 2 diabetes mellitus (T2DM) and heart failure on metformin, and (2) heart failure without T2DM and metformin naïve.

METHODS

Two prospective studies on heart failure patients were undertaken. The first was a cross-sectional study with two patient cohorts, one with T2DM on metformin (n=44) and one without T2DM metformin naive (n=47). The second was a 12-week interventional study of patients without T2DM (n=27) where metformin (500 mg immediate release, twice daily) was prescribed. Plasma metformin and lactate concentrations were monitored. Individual pharmacokinetics were compared between cohorts. Univariable and multivariable analysis analysed the effects of variables on plasma lactate concentrations.

RESULTS

Plasma metformin and lactate concentrations mostly (99.9%) remained below safety thresholds (5 mg/L and 5 mmol/L, respectively). Metformin concentration had no significant relationship with lactic acidosis safety markers. In the interventional study, New York Heart Association (NYHA) II (p<0.03) and III (p<0.001) grading was associated with higher plasma lactate concentrations, whereas male sex was associated with 47% higher plasma lactate concentrations (p<0.05). The pharmacokinetics of heart failure patients with and without T2DM were similar.

CONCLUSIONS

We observed no unsafe plasma lactate concentrations in patients with heart failure treated with metformin. Metformin exposure did not influence plasma lactate concentrations; however, NYHA class and sex did. The pharmacokinetics of metformin in heart failure patients are similar irrespective of T2DM. These findings may support the safe use of metformin in heart failure patients with and without T2DM.

Core Surface Flow Changes Associated With the 2017 Pacific Geomagnetic Jerk

A geomagnetic jerk was seen in Swarm satellite data in 2017 over the Pacific region. We invert time series of spatial gradient secular variation data between 2014 and 2020, reduced to a grid of points at satellite altitude, for spatially- and temporally-regularized core surface flow. Pacific region flow acceleration was almost constant before and after the jerk, with a sharp change, especially in the azimuthal component, at the jerk epoch, despite the temporal regularization. Azimuthal acceleration is oppositely signed either side of 160°W, where it effectively vanishes, and also reverses sign at the jerk epoch. Acceleration features drift westward at about 900 km year^-1. Unlike previous studies, the evidence presented here for low latitude waves does not depend on imposing flow equatorial symmetry, quasi- or tangential geostrophy, or band-pass filtering, and has no reliance on stochastic models or numerical simulations.

The essential role of costimulatory molecules in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic inflammatory disease with immune system disorder mediated through complex autoimmune pathways that involve immune cells, nonimmune cells, cytokines, chemokines, as well as costimulatory molecules. Costimulatory signals play a critical role in initiating, maintaining and regulating immune reactions, and these include ligands and receptors and their interactions involving multiple types of signal information. Dysfunction of costimulatory factors results in complicated abnormal immune responses, with biological effects and eventually, clinical autoimmune diseases. Here we outline what is known about various roles that costimulatory families including the B7 family and tumor necrosis factor super family play in SLE. The aim of this review is to understand the possible association of costimulation with autoimmune diseases, especially SLE, and to explore possible therapeutic target(s) of costimulatory molecules and pathways that might be used to develop therapeutic approaches for patients with these conditions.

Asbestos exposure and histological subtype of malignant mesothelioma

BACKGROUND

Malignant mesothelioma (MM) has distinct histological subtypes (epithelioid, sarcomatoid and biphasic) with variable behaviour and prognoses. It is well recognised that survival time varies with the histological subtype of MM. It is not known, however, if asbestos exposure characteristics (type of asbestos, degree of exposure) are associated with different histological subtypes.

AIM

To determine if the pathological MM subtype is associated with the type of asbestos or the attributes of asbestos exposure.

METHODS

Cases of MM for the period 1962 until 2012, their main histological subtype and their most significant source of asbestos exposure were collected from the Western Australian Mesothelioma Registry. Exposure characteristics included, degree of asbestos exposure (including total days exposed, years since first exposure and, for crocidolite only, calculated cumulative exposure), source of exposure (occupational or environmental), form of asbestos handled (raw or processed) and type of asbestos (crocidolite only or mixed fibres).

RESULTS

Patients with the biphasic subtype were more likely to have occupational exposure (OR 1.83, 1.12 to 2.85) and exposure to raw fibres (OR 1.58, 1.19 to 2.10). However, differences between subtypes in the proportions with these different exposure characteristics were small and unlikely to be biologically relevant. Other indicators of asbestos exposure were not associated with the histological subtype of mesothelioma.

CONCLUSIONS

There was no strong evidence of a consistent role of asbestos exposure indicators in determining the histological subtype of MM.

First Report of Zebra Chip Disease and "Candidatus Liberibacter solanacearum" on Potatoes in Idaho

In September 2011, potato (Solanum tuberosum L.) tubers graded in a packing facility in south-central Idaho were observed with internal discolorations suggestive of zebra chip disease (ZC). Symptoms were observed in 1 to 2% of tubers of cv. Russet Norkotah and included brown spots and streaks especially in and near the vascular tissue. Some tubers also showed a dark and sunken stolon attachment typical of ZC (1). Initially, tissue samples were taken from seven symptomatic tubers and tested by PCR for "Candidatus Liberibacter solanacearum", the bacterium associated with ZC. Primers specific for the 16S rDNA (primers CLipoF [4] and OI2c [3]) and the outer membrane protein (OMB 1482f and 2086r) (2) were used. Six of these samples were positive for the bacterium. The amplified 16S rDNA and OMB products from two symptomatic tubers of cv. Russet Norkotah were cloned and three clones of each were sequenced. The 16S sequences (1,071 bp; GenBank Accession Nos. JN848755 and JN848756) from the two tubers varied by one nucleotide and had 99 to 100% sequence identity to numerous "Ca. L. solanacearum" sequences in GenBank (e.g., Accession Nos. HM246509, FJ957897, and EU935004). Sequences of the two OMB clones (605 bp; GenBank Accession Nos. JN848757 and JN848758) had 97% sequence identity to the two "Ca. L. solanacearum" OMB sequences in GenBank (Accession Nos. CP002371 and FJ914617). Six of eight additional symptomatic field-collected cv. Russet Norkotah tubers corresponding to tubers collected in the packing facility were also positive for "Ca. L. solanacearum" by PCR. Additional severely symptomatic tubers of cvs. Russet Burbank, Yukon Gold, and raw cut French fries of Ranger Russet produced in south-central Idaho were subsequently tested by PCR and were found to be positive for "Ca. L. solanacearum" as well. On the basis of the symptoms, specific PCR amplification with two distinct primer pairs and DNA sequence analysis, zebra chip disease caused by "Ca. L. solanacearum" was determined to be present in Idaho. This disease has caused significant economic damage to potatoes in many regions, including Texas, Mexico, Central America, and New Zealand (1). Idaho is the largest potato-producing state in the United States, with over 150,000 ha planted this year, and therefore, ZC potentially poses a significant risk to agriculture in this state. References: (1) J. M. Crosslin et al. Online publication. doi:10.1094/PHP-2010-0317-01-RV, Plant Health Progress, 2010. (2) J. M. Crosslin et al. Southwest. Entomol. 36:125, 2011. (3) S. Jagoueix et al. Mol. Cell. Probes 10:43, 1996. (4) G. A. Secor. Plant Dis. 93:574, 2009.

Predicting survival in malignant mesothelioma

Malignant mesothelioma (MM) of the pleura or peritoneum is a universally fatal disease attracting an increasing range of medical interventions and escalating healthcare costs. Changes in survival and the factors affecting survival of all patients ever diagnosed with MM in Western Australia over the past five decades and confirmed by the Western Australian Mesothelioma Registry to December 2005 were examined. Sex, age, date and method of diagnosis, site of disease and histological type were recorded. Date of onset of symptoms and performance status were obtained from clinical notes for a sample of cases. Cox regression was used to examine the association of the clinical variables and the 10-yr periods of disease onset with survival after diagnosis. Survival was inversely related to age, being worse for males (hazard ratio (HR) 1.4, 95% CI 1.2-1.6), and those with peritoneal mesothelioma (HR 1.4, 95% CI 1.1-1.7). Patients with sarcomatoid histology had worse prognosis than patients with epithelioid and biphasic histological subtypes. Survival improved after the 1970s and has made incremental improvements since then. Median (interquartile range) survival by decade, from 1960 until 2005, was 64 (0-198), 177 (48-350), 221 (97-504), 238 (108-502) and 301 (134-611) days; ~4 weeks of this apparent improvement can be attributed to earlier diagnosis. With increasing resources and treatment costs for MM over the past 40 yrs, there have been modest improvements in survival but no complete remissions.

Identification of Potato virus Y Strains Associated with Tuber Damage During a Recent Virus Outbreak in Potato in Idaho

Potato virus Y (PVY) causes substantial losses in potato production by decreasing yields and affecting the quality of potato tubers. Management of PVY in potato is dependent primarily on potato seed certification programs to prevent or limit initial levels of virus inoculum. Prior to 1990, the ordinary strain of PVY (PVY^O) was the predominant virus in North America. PVY^O induces clear foliar symptoms in many potato cultivars, allowing successful management in seed potato through a combination of visual inspections and limited laboratory testing. In recent years, necrotic strains of PVY (PVY^N, PVY^NTN, and PVY^N:O) have begun to spread in the United States, many of which induce mild symptoms in potato, making them more difficult to manage through visual inspections. In addition to reducing yield, necrotic isolates may also cause external and internal damage in tubers of susceptible cultivars, which is known as potato tuber necrotic ringspot disease (PTNRD). Tuber necrotic strains of PVY have been reported across the northern United States (1,2,4), although limited information is available on their incidence and spread in commercial potato production. During June and July of 2007, 38 random samples were collected from three different commercial fields displaying disease problems (cvs. Russet Ranger, Alturas, and Russet Burbank) in the vicinity of Idaho Falls, ID. Plants collected showed various degrees of mosaic and leaf yellowing. By using double-antibody sandwich (DAS)-ELISA and reverse transcription (RT)-PCR, 25 of these plants were identified as PVY positive. The mutiplex RT-PCR assay (3) confirmed that nine plants were infected with PVY^NTN and 11 with PVY^N:O. No RT-PCR products were amplified from five samples. During September and October of 2007, 25 tuber samples (cv. Russet Burbank) showing various degrees of unusual internal symptoms (e.g., brown spots) were collected near Idaho Falls, ID. Twenty-two tubers were found PVY positive by DAS-ELISA, and multiplex RT-PCR determined 13 of those were PVY^NTN, three were PVY^O, one was a PVY^NTN/N:O mixture, and one was a PVY^O/N:O mixture. No RT-PCR products were amplified from four samples. In October 2007, six tubers showing distinct external tuber damage characteristic of PTNRD (cv. Highland Russet) were collected near Twin Falls, ID. All six tubers were determined to be PVY positive by DAS-ELISA, and RT-PCR identified five as infected with PVY^NTN and one with PVY^N:O. All the mixtures were easily separated by inoculating tobacco plants followed by subsequent testing of individual plants. Asymptomatic tubers from the same lot not showing PTNRD damage were found PVY negative by DAS-ELISA and RT-PCR. All PVY^NTN isolates collected during 2007 were inoculated into tobacco plants (Nicotiana tabacum L. cv. Xanthi) and confirmed to induce systemic vein necrosis. Limited sequencing of four of the PVY^NTN isolates determined that they contained recombinant junctions 2 and 3, identifying them as being related to the European strain of PVY^NTN (3). The data suggest an increase in distribution and incidence of necrotic strains of PVY in commercial, potato-production areas in Idaho during an outbreak in 2007 and the potential for an increase in PTNRD. References: (1) P. M. Baldauf et al. Plant Dis. 90:559, 2006. (2) J. M. Crosslin et al. Plant Dis. 90:1102, 2006. (3) J. H. Lorenzen et al. Plant Dis. 90:935, 2006. (4) L. M. Piche et al. Phytopathology 94:1368, 2004.

The effect of asbestosis on lung cancer risk beyond the dose related effect of asbestos alone

AIMS

To determine if the presence of asbestosis is a prerequisite for lung cancer in subjects with known exposure to blue asbestos (crocidolite).

METHODS

Former workers and residents of Wittenoom with known amounts of asbestos exposure (duration, intensity, and time since first exposure), current chest x ray and smoking information, participating in a cancer prevention programme (n = 1988) were studied. The first plain chest radiograph taken at the time of recruitment into the cancer prevention programme was examined for radiographic evidence of asbestosis according to the UICC (ILO) classification. Cox proportional hazards modelling was used to relate asbestosis, asbestos exposure, and lung cancer.

RESULTS

Between 1990 and 2002 there were 58 cases of lung cancer. Thirty six per cent of cases had radiographic evidence of asbestosis compared to 12% of study participants. Smoking status was the strongest predictor of lung cancer, with current smokers (OR = 26.5, 95% CI 3.5 to 198) having the greatest risk. Radiographic asbestosis (OR = 1.94, 95% CI 1.09 to 3.46) and asbestos exposure (OR = 1.21 per f/ml-year, 95% CI 1.02 to 1.42) were significantly associated with an increased risk of lung cancer. There was an increased risk of lung cancer with increasing exposure in those without asbestosis.

CONCLUSION

In this cohort of former workers and residents of Wittenoom, asbestosis is not a mandatory precursor for asbestos related lung cancer. These findings support the hypothesis that it is the asbestos fibres per se that cause lung cancer, which can develop with or without the presence of asbestosis.

The additional risk of malignant mesothelioma in former workers and residents of Wittenoom with benign pleural disease or asbestosis

AIMS

To examine the hypothesis that people with benign pleural disease or asbestosis have an increased risk of malignant mesothelioma beyond that attributable to their degree of asbestos exposure.

METHODS

Former workers and residents of the crocidolite mining and milling town of Wittenoom are participating in a cancer prevention programme (n = 1988). The first plain chest radiograph taken at the time of recruitment into the cancer prevention programme was read for evidence of benign pleural disease and asbestosis, using the UICC classification. Crocidolite exposure of former workers was derived from employment records and records of dust measurements performed during the operation of the asbestos mine and mill between 1943 and 1966. Based on fibre counts, exposure for former residents was determined using duration of residence and period of residence (before and after a new mill was commissioned in 1957) and interpolation from periodic hygienic measures undertaken from personal monitors between 1966 and 1992. Cox proportional hazards modelling was used to relate benign pleural disease, asbestosis, asbestos exposure, and mesothelioma.

RESULTS

Between 1990 and 2002, there were 76 cases of mesothelioma (56 of the pleura and 20 of the peritoneum). Cases had more radiographic evidence of (all) benign pleural disease, pleural thickening, blunt/obliterated costophrenic angle, and asbestosis than non-cases. Adjusting for time since first exposure (log years), cumulative exposure (log f/ml-years), and age at the start of the programme, pleural thickening (OR = 3.1, 95% CI 1.2 to 7.6) and asbestosis (OR = 3.3, 95% CI 1.3 to 8.6) were associated with an increased risk of peritoneal mesothelioma. There was no increased risk for pleural mesothelioma.

CONCLUSION

The presence of benign pleural disease, in particular pleural thickening, and asbestosis appears to increase the risk of mesothelioma of the peritoneum, but not of the pleura beyond that attributable to indices of asbestos exposure in this cohort of subjects exposed to crocidolite.

Effects of asbestos and smoking on the levels and rates of change of lung function in a crocidolite exposed cohort in Western Australia

BACKGROUND

Increased rates of death from asbestos related diseases have been reported in former workers and residents exposed to crocidolite (blue asbestos) at Wittenoom, Western Australia. Exposure to asbestos is associated with reduced static lung volumes, gas transfer and lung compliance, and a restrictive ventilatory abnormality.

METHODS

The effects of crocidolite exposure and smoking history on levels and rates of change of lung function were evaluated using a linear mixed model. Lung function was measured as forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC.

RESULTS

Cumulative doses of asbestos and the presence of radiographic asbestosis were associated with lower levels of FEV1 and FVC and a steeper decline during the period of observation. Subjects exposed to asbestos at a younger age had lower levels of FEV1 and FVC. Current smokers had lower levels and a steeper decline in lung function than never smokers. No significant interactions between crocidolite exposure and smoking on the levels or rates of change of lung function were found.

CONCLUSIONS

The deleterious effects of crocidolite exposure on lung function persist in this population, despite asbestos exposure having ceased more than 30 years ago. No significant interactions were found in this population between asbestos and smoking at the first visit or longitudinally.

A gene expression signature for recent onset rheumatoid arthritis in peripheral blood mononuclear cells

BACKGROUND

In previous studies the presence of a distinct gene expression pattern has been shown in peripheral blood cells from patients with autoimmune disease.

OBJECTIVE

To determine whether other specific signatures might be used to identify subsets of these autoimmune diseases and whether gene expression patterns in early disease might identify pathogenetic factors.

METHODS

Peripheral blood mononuclear cells were acquired from patients with rheumatoid arthritis (RA) and analysed by microarrays containing over 4300 named human genes. Patients with RA for <2 years were compared with subjects with longstanding RA (average duration 10 years) and with patients with other immune or autoimmune diagnoses.

RESULTS

Cluster analyses permitted separation of the patients with early RA (ERA) from those with longstanding disease. Comparison with other patient groups suggested that the ERA signature showed some overlap with that seen in the normal immune response to viral antigen as well as with a subset of patients with systemic lupus erythematosus.

CONCLUSIONS

The ERA signature may reflect, in part, a response to an unknown infectious agent. Furthermore, shared features with some lupus patients suggest that common aetiological factors and pathogenetic pathways may be involved in these two autoimmune disorders.

Colorectal transport in normal defaecation

OBJECTIVE

Colorectal luminal transport during defaecation can be assessed by means of scintigraphy. However, normal values remain to be established and inter- and intra-subjective variation is unknown. The aim of the study was to describe colorectal transport during normal defaecation by means of a new method for colorectal scintigraphy and to determine inter- and intrasubjective variation.

METHODS

Thirty healthy volunteers (18 men and 12 women, age 22-46 years; median 31) took 2 MBq 111In on two consecutive days (days 0 and 1). On days 1 and 2 an abdominal scintigraphy was done before and after defaecation. Changes in colorectal contents were computed in two ways: firstly, assuming ordered evacuation, the extent of colorectal emptying was computed; secondly, antegrade and retrograde transport within the colorectum was computed for each colorectal segment.

RESULTS

Median colorectal emptying during normal defaecation was 99% of the rectosigmoid (range: 60% of the rectosigmoid to complete emptying of the rectosigmoid, descending colon, transverse colon and 19% of the caecum/ascending colon). There was no difference between men (median 99% of the rectosigmoid) and women (98% of the rectosigmoid). Day to day variation was large (dispersion=52%) with a trend towards larger defaecation on day 2 than on day 1 (P = 0.09). Large antegrade and retrograde movements of colorectal contents were observed within the colorectum during defaecation. Antegrade transport involved the rectosigmoid (median 99%), the descending colon (median 53%), the transverse colon (median 46%), and the caecum/ascending colon (median 11%). Retrograde transport was mainly from the transverse colon and the descending colon. Colorectal emptying was significantly correlated to the subjective description (P < 0.01) but not to total gastrointestinal or segmental colorectal transit times determined by means of radioopaque markers.

CONCLUSIONS

Colorectal scintigraphy before and after defaecation provides detailed information about colorectal emptying and intracolonic antegrade or retrograde transport during defaecation. Inter- and intraindividual variations are large and antegrade and retrograde transport within the colorectum is common.

Colorectal transport during defecation in patients with lesions of the sacral spinal cord

Normal defecation involves reflexes between the colorectum and sacral spinal cord. Lesions of the conus medullaris or cauda equina interrupt such reflex arches and cause constipation. The aim of the study was to compare colorectal transport during defecation in patients with sacral spinal cord lesions and healthy volunteers. Ten patients with sacral spinal cord lesions (six men and four women, age 21-57 y, median = 36) and 16 healthy volunteers (10 men and six women, age 22-42 y, median = 30) took one or two doses of 111In-labelled polystyrene pellets perorally to mark colorectal contents. Abdominal scintigraphy was performed before and after defecation. Total colorectal emptying and segmental antegrade or retrograde transport was computed. Median colorectal emptying during normal defecation was 81% of the rectosigmoid (range: 53% of the rectosigmoid to complete emptying of the rectosigmoid and 40% of the descending colon) in healthy volunteers and 27% of the rectosigmoid (range: 0-44% of the rectosigmoid) in patients with conal/cauda equina lesions (P < 0.001). Median antegrade transport was 82% (control group) vs 27% (patients) of the rectosigmoid (P < 0.001), 38% vs 4% of the descending colon (P < 0.02), 13% vs 1% of the transverse colon (P = 0.28), and 4% vs 2% of the caecum/ascending colon (P = 0.76). It is concluded that damage to reflex arches between the colorectum and the sacral spinal cord significantly reduces emptying of the rectosigmoid and descending colon during defecation.

Scintigraphic assessment of antegrade colonic irrigation through an appendicostomy or a neoappendicostomy

Background

The aim of this study was to evaluate large bowel transport following antegrade colonic irrigation with a new scintigraphic technique.

Methods

Ten patients (eight with severe constipation, two with faecal incontinence; median age 47 (range 41–66) years) treated with antegrade colonic irrigation took 111In-labelled polystyrene pellets to label the bowel contents. 99mTc-labelled diethylenetriamine penta-acetate was mixed with the irrigation fluid to map its distribution within the large bowel. Scintigraphy was performed before and after a standardized irrigation procedure. The large bowel was divided into four segments. Assuming ordered evacuation of the large bowel, the contribution of each colonic segment to total evacuation was expressed as a percentage of original segmental count. The segmental contributions were added to reach a total defaecation score (range 0–400).

Results

The median defaecation score was 350, corresponding to complete emptying of the rectosigmoid, descending colon, transverse colon, and half of the caecum and ascending colon. The retained irrigation fluid was located throughout the large bowel. Back-flow to the ileum was observed in four patients.

Conclusion

This study used a new scintigraphic technique to assess large bowel transport following antegrade colonic irrigation. Antegrade colonic irrigation induces highly effective emptying even in patients with severe constipation.

Scintigraphic assessment of colostomy irrigation

OBJECTIVE: This study aims to evaluate colonic transport following colostomy irrigation with a new scintigraphic technique. MATERIALS AND METHODS: To label the bowel contents 19 patients (11 uncomplicated colostomy irrigation, 8 complicated colostomy irrigation) took 111In-labelled polystyrene pellets one and two days before investigation. 99mTc-DTPA was mixed with the irrigation fluid to assess its extent within the bowel. Scintigraphy was performed before and after a standardized washout procedure. The colon was divided into three segments 1: the caecum andascending colon; 2: the transverse colon; 3: the descending and sigmoid colon. Assuming ordered evacuation of the colon, the contribution of each colonic segment to the total evacuation was expressed as a percentage of the original segmental counts. These were added to reach a total defaecation score (range: 0-300). RESULTS: In uncomplicated colostomy irrigation, the median defaecation score was 235 (range: 145-289) corresponding to complete evacuation of the descending and transverse colon and 35% evacuation of the caecum/ascending colon. In complicated colostomy irrigation it was possible to distinguish specific emptying patterns. The retained irrigation fluid reached the caecum in all but one patient. CONCLUSION: Scintigraphy can be used to evaluate colonic emptying following colostomy irrigation.

Two-year, blinded, randomized, controlled trial of treatment of active rheumatoid arthritis with leflunomide compared with methotrexate. Utilization of Leflunomide in the Treatment of Rheumatoid Arthritis Trial Investigator Group

OBJECTIVE

Three 6-12-month, double-blind, randomized, controlled trials have shown leflunomide (LEF; 20 mg/day, loading dose 100 mg x 3 days) to be effective and safe for the treatment of rheumatoid arthritis (RA). This analysis of the North American trial assessed whether the clinical benefit evident at month 12 was sustained over 24 months of treatment with LEF as compared with the efficacy and safety of methotrexate (MTX), an equivalent disease-modifying antirheumatic drug, at 24 months.

METHODS

The year-2 cohort, comprising patients continuing into the second year of treatment with > or = 1 dose of study medication and > or = 1 followup visit after week 52, consisted of 235 patients (LEF n = 98; placebo n = 36; MTX n = 101). The mean (+/- SD) maintenance dose of LEF was 19.6 +/- 1.99 mg/day in year 2 and that of MTX was 12.6 +/- 4.69 mg/week. Statistical analyses used an intent-to-treat (ITT) approach. Statistical comparisons of the active treatments only were prospectively defined in the protocol.

RESULTS

In total, 85% and 79% of LEF and MTX patients, respectively, who entered year 2 completed 24 months of treatment. From month 12 to month 24, the American College of Rheumatology improvement response rates of > or = 20% (LEF 79% versus MTX 67%; P = 0.049), > or = 50% (LEF 56% versus MTX 43%; P = 0.053), and > or = 70% (LEF 26% versus MTX 20%; P = 0.361) were sustained in both of the active treatment groups. The mean change in total Sharp radiologic damage scores at year 2 compared with year 1 and baseline (LEF 1.6 versus MTX 1.2) showed statistically equivalent sustained retardation of radiographic progression in the active treatment groups. Maximal improvements evident at 6 months in the Health Assessment Questionnaire (HAQ) disability index (HAQ DI) and the physical component score of the Medical Outcomes Survey 36-item short form were sustained over 12 months and 24 months; improvement in the HAQ DI with LEF4(-0.60) was statistically significantly superior to that with MTX (-0.37) at 24 months (P = 0.005). Over 24 months in the ITT cohort, serious treatment-related adverse events were reported in 1.6% of the LEF-treated patients and 3.7% of the MTX-treated patients. Frequently reported adverse events included upper respiratory tract infections, diarrhea, nausea and vomiting, rash, reversible alopecia, and transient liver enzyme elevations.

CONCLUSION

The safety and efficacy of LEF and MTX were maintained over the second year of this 2-year trial. Both active treatments retarded radiographic progression over 24 months. LEF was statistically significantly superior to MTX in improving physical function as measured by the HAQ DI over 24 months of treatment. Results indicate that LEF is a safe and effective initial treatment for active RA, with clinical benefit sustained over 2 years of treatment without evidence of new or increased toxicity.

Expression of somatostatin receptors on human pituitary adenomas in vivo and ex vivo

The distribution and biologic activity of somatostatin receptor subtypes (SSTR) in pituitary adenomas is not clarified, especially regarding clinically non-functioning adenomas (NFPA). We therefore characterized SSTR in human pituitary adenomas by combining molecular biology and in vivo scintigraphy. Co-expression of gonadotropin-releasing hormone receptor (GnRH-R) mRNA was also assessed to see whether this feature was associated with adenoma subtype and SSTR status. Pituitary tumor biopsies were obtained during transsphenoidal adenomectomy from 21 patients (11 NFPA, 7 acromegalics, 2 prolactinomas, 1 Cushing's disease). Expression of mRNA encoding the 5 known SSTR subtypes and the GnRH-R was determined by RT-PCR. Twelve patients also underwent a pre-operative somatostatin receptor scintigraphy. Most adenomas (no.=18) expressed mRNA for more than one SSTR. SSTR2 mRNA was expressed in 18 cases, whereas SSTR4 was absent in all but one. SSTR3 was frequently expressed in NFPAs. Somatostatin receptor scintigraphy was positive in most cases, and with a significantly higher uptake index in GH-producing adenomas all of which expressed SSTR2 mRNA. The uptake index appeared to be related to receptor density rather than tumor volume. Expression of GnRH-R mRNA was found in both NFPAs and GH-producing adenomas and was not significantly associated with a particular SSTR subtype population.

IN CONCLUSION

1) the distribution of SSTR is not significantly different between NFPA and GH-producing adenomas; and 2) somatostatin receptor scintigraphy reveals a higher uptake in GH-producing adenomas which is not significantly related to either SSTR distribution or tumor volume.

Alterations in the regulation of androgen-sensitive Cyp 4a monooxygenases cause hypertension

Hypertension is a leading cause of cardiovascular, cerebral, and renal disease morbidity and mortality. Here we show that disruption of the Cyp 4a14 gene causes hypertension, which is, like most human hypertension, more severe in males. Male Cyp 4a14 (-/-) mice show increases in plasma androgens, kidney Cyp 4a12 expression, and the formation of prohypertensive 20-hydroxyarachidonate. Castration normalizes the blood pressure of Cyp 4a14 (-/-) mice and minimizes Cyp 4a12 expression and arachidonate omega-hydroxylation. Androgen replacement restores hypertensive phenotype, Cyp 4a12 expression, and 20-hydroxy-arachidonate formation. We conclude that the androgen-mediated regulation of Cyp 4a arachidonate monooxygenases is an important component of the renal mechanisms that control systemic blood pressures. These results provide direct evidence for a role of Cyp 4a isoforms in cardiovascular physiology, establish Cyp 4a14 (-/-) mice as a monogenic model for the study of cause/effect relationships between blood pressure, sex hormones, and P450 omega-hydroxylases, and suggest the human CYP 4A homologues as candidate genes for the analysis of the genetic and molecular basis of human hypertension.

Evidence for metabolic abnormalities in the muscles of patients with fibromyalgia

Widespread muscle pain, fatigue, and weakness are defining characteristics of patients with fibromyalgia (FM). The aim of this review is to summarize recent investigations of muscle abnormalities in FM, which can be classified as structural, metabolic, or functional in nature. Histologic muscle abnormalities of membranes, mitochondria, and fiber type have been well described at both the light microscopic and ultrastructural levels. These structural abnormalities often correlate with biochemical abnormalities, defective energy production, and the resultant dysfunction of FM muscles. The observed abnormalities in FM muscles are consistent with neurologic findings and disturbances in the hypothalamic-pituitary-adrenal axis. Functional changes in FM muscles are assessed most directly by strength and endurance measurements, but pain and psychologic factors may interfere with accurate assessments. To compensate for diminished effort, the decreased efficiency of the work performance by patients with FM can be verified from P-31 magnetic resonance spectroscopy (MRS) data by calculation of the work/energy-cost ratio for various tasks. In the disease course, muscle abnormalities may be elicited by intrinsic changes within the muscle tissue itself and/or extrinsic neurologic and endocrine factors. The accurate assignment of intrinsic or extrinsic factors has been substantially clarified by a recent surge of experimental findings. Irrespective of the multifaceted causes of muscle dysfunction and pain, an in-depth understanding of the muscle defects may provide ideas for characterization of the underlying pathogenesis and development of new therapeutic approaches for fibromyalgia syndrome.

Treatment of active rheumatoid arthritis with leflunomide compared with placebo and methotrexate. Leflunomide Rheumatoid Arthritis Investigators Group

CONTEXT

Leflunomide is a reversible inhibitor of de novo pyrimidine synthesis shown to be effective in a phase 2 trial in 402 patients with active rheumatoid arthritis (RA).

OBJECTIVE

To compare the efficacy and safety of leflunomide treatment with placebo and methotrexate treatment in patients with active RA.

DESIGN

Randomized, double-blind, placebo, and active-controlled 12-month study.

SETTING

Forty-seven university and private rheumatology practices in the United States and Canada.

PATIENTS

Diagnosis of RA by the American College of Rheumatology (ACR) criteria for duration of 6 months or longer and no previous methotrexate treatment.

INTERVENTION

Leflunomide treatment (20 mg/d), placebo, or methotrexate treatment (7.5-15 mg/wk).

MAIN OUTCOME MEASURES

American College of Rheumatology success rate (completed 52 weeks of treatment and met the ACR > or = 20% response criteria), disease progression as assessed by x-ray films, and improvement in function and health-related quality of life using the intent-to-treat population.

RESULTS

The 482 patients studied were predominantly women (mean age, 54 years; mean disease duration, 6.7 years) for whom a mean of 0.8 disease-modifying antirheumatic drugs had failed. The ACR response and success rates for patients receiving leflunomide treatment (52% and 41%, respectively) and methotrexate treatment (46% and 35%, respectively) were significantly higher than those for patients receiving placebo (26% and 19%, respectively) (P<.001), and they were statistically equivalent, with mean time to initial response at 8.4 weeks for patients receiving leflunomide vs 9.5 weeks for patients receiving methotrexate therapy. X-ray analyses demonstrated less disease progression with leflunomide (P=.001) and methotrexate (P = .02) therapy than with placebo. Leflunomide and methotrexate treatment improved measures of physical function and health-related quality of life significantly more than placebo (P<.001 and P<.05, respectively). Common adverse events for patients receiving leflunomide treatment included gastrointestinal complaints, skin rash, and reversible alopecia. Asymptomatic transaminase elevations resulted in treatment discontinuations for 7.1% of patients receiving leflunomide therapy, 1.7% of patients receiving placebo, and 3.3% of patients receiving methotrexate therapy.

CONCLUSIONS

Clinical responses following administration of leflunomide, a new therapeutic agent for the treatment of RA, were statistically superior to those with placebo and equivalent to those with methotrexate treatment. Both active treatments improved signs and symptoms of active RA, delayed disease progression as demonstrated by x-ray films, and improved function and health-related quality of life.

Vitamin A and cancer prevention II: comparison of the effects of retinol and beta-carotene

Former blue asbestos workers known to be at high risk of asbestos-related diseases, particularly malignant mesothelioma and lung cancer, were enrolled in a chemo-prevention program using vitamin A. Our aims were to compare rates of disease and death in subjects randomly assigned to beta-carotene or retinol. Subjects were assigned randomly to take 30 mg/day beta-carotene (512 subjects) or 25,000 IU/day retinol (512 subjects) and followed up through death and cancer registries from the start of the study in June 1990 till May 1995. Comparison between groups was by Cox regression in both intention-to-treat analyses and efficacy analyses based on treatment actually taken. Median follow-up time was 232 weeks. Four cases of lung cancer and 3 cases of mesothelioma were observed in subjects randomised to retinol and 6 cases of lung cancer and 12 cases of mesothelioma in subjects randomised to beta-carotene. The relative rate of mesothelioma (the most common single cause of death in our study) for those on retinol compared with those on beta-carotene was 0.24 (95% CI 0.07-0.86). In the retinol group, there was also a significantly lower rate for death from all causes but a higher rate of ischaemic heart disease mortality. Similar results were found with efficacy analyses. Our results confirm other findings of a lack of any benefit from administration of large doses of synthetic beta-carotene. The finding of significantly lower rates of mesothelioma among subjects assigned to retinol requires further investigation.

Cardiac function during iron chelation therapy in adult non-thalassaemic patients with transfusional iron overload

It is well-documented that iron chelation by desferrioxamine protects/improves the cardiac function in blood transfusion-dependent children suffering from beta-thalassaemia. In patients who do not become dependent upon blood transfusion until adulthood (ANT-patients), iron chelation by desferrioxamine may affect the cardiac function in unknown ways, presumably because age-related changes in the heart may cause iron chelation to affect the cardiac function in different ways. We therefore followed the left ventricular ejection fraction (LVEF) by multigated radionuclide angiography in 16 iron-loaded ANT-patients during iron chelation alone and after increasing the efficacy of chelation by vitamin C supplementation. During 12 months of iron chelation the mean LVEF fell significantly from 63.3% to 58.0% (p=0.04). Individual changes in LVEF did not correlate significantly with age but with the pretreatment liver iron concentration. After initiation of vitamin C supplementation, the mean LVEF increased from 55.9% to 65.3% (p=0.01). Our data suggest that in ANT-patients prolonged desferrioxamine treatment without vitamin C supplementation may be associated with reduced LVEF, whereas vitamin C supplementation seems to benefit the cardiac function. Similar findings have not been described in beta-thalassaemia and may hence be specific for ANT-patients. However, our findings have to be confirmed by controlled studies.

Microsatellite instability analysis of primary human brain tumors

Microsatellite instability, as shown by the presence of additional alleles or shifts of electrophoretic mobility at simple sequence tandem repeat loci, has been demonstrated in hereditary and sporadic colorectal tumors and many other tumor types. To study microsatellite instability in human brain tumors, we examined a total of 144 sporadic neoplasms. These included 33 astrocytic tumors, 23 oligodendrogliomas, six gangliogliomas, 41 meningiomas, 10 vestibular schwannomas and 31 pituitary adenomas. Di-, tri- and tetranucleotide repeat microsatellite markers localized on chromosome 4 and 9, X, 13 and 22, respectively, were used to assess whether instability was a significant aspect of their abnormal chromosomal pattern. Instability of microsatellite markers was detected in four oligodendrogliomas (17.4%), one pituitary adenoma (3.2%), one meningioma (2.4%), one astrocytic tumor (3.0%) and not at all in gangliogliomas and schwannomas. Therefore, our results suggest that the microsatellite instability which occurs in colorectal cancers with defective mismatch repair is infrequent in many types of human brain tumors and that the lower level of instability observed in brain tumors may be reflective of other mechanisms of genetic instability.

Familial scleroderma--evidence for environmental versus genetic trigger

Families with more than one case of scleroderma are unusual. Four families each with two members (in one case monozygotic twins) with scleroderma (systemic sclerosis, SSc) were identified. Clinical, immunogenetic and autoantibody studies were carried out. Multicase SSc families cited in the literature were reviewed. Each family pair shared cutaneous subset of disease severity, and SSc-associated autoantibody. HLA typing showed two pairs shared an HLA-DR allele associated with scleroderma (DR3 or DR5), while one also had alleles reported in association with their SSc-specific autoantibody. Review of dates and ages of onset suggested that the timing of onset of scleroderma is more likely to have an environmental trigger than to be encoded genetically.

Mutation analysis of coding sequences for type I procollagen in individuals with low bone density

Mutations in one of the two genes encoding type I procollagen (COL1A1 and COL1A2) are frequently the cause of osteogenesis imperfecta (OI), a disorder characterized by brittle bones. Here we tested whether patients with low bone density also have mutations in these genes. The 26 patients studied had no apparent metabolic bone disease, but most had a positive family history of osteopenia or osteoporosis. Although a diagnosis of OI was considered by the clinician in some cases, the clinical criteria for OI were not satisfied. Our strategy for mutation analysis consisted of PCR amplification of cDNA made to fibroblast mRNA using primers specific for the coding regions of COL1A1 and COL1A2. The PCR products were then sequenced directly with primers located within each PCR product. We found that 3 of 26 patients had mutations that altered the encoded amino acid. One mutation, at position alpha 2(I)-661 has been reported (Spotila et al. 1991 Proc Natl Acad Sci USA PNAS 88:5423). The other 2 patients, who were not related to each other, had a mutation that altered the proline codon at alpha 1(I)-27 to alanine. This mutation was not found in 81 normal individuals or in 37 additional osteopenic individuals. However, its effect on the biologic function of type I collagen, as well as its role in osteopenia, is uncertain. In addition to the two mutations, we found a polymorphism in codon alpha 2(I)-459. Although this polymorphism involved an amino acid substitution, it was present with equal frequency in the patient and the normal population. By analyzing this and previously reported neutral sequence variants in the COL1A2 gene, we determined that all patients expressed both alleles of the COL1A2 gene. The 12 patients who were heterozygous for a COL1A1 neutral sequence variant also expressed both alleles. Here we present all PCR primer and sequencing primer information. The results suggest that surveying a larger group of similarly selected individuals may reveal additional mutations in the COL1A1 or COL1A2 genes.

Vibration aftereffects on vasoconstrictor response to cold in the normal finger

The acute effects of unilateral 30 min exposure to hand-arm vibration on the vasoconstrictor response to cold in a finger from both hands were investigated in 12 healthy men (age 18-38 years) who had never worked with vibrating tools. One hand was exposed to accelerations of 4.0 and 16.0 m.s-2 on 2 different days. The vasoconstrictor response to cold (R%) was expressed as the relative decrease in finger systolic blood pressure, measured using cuff and strain gauge techniques, when the finger was cooled from 30 to 10 degrees C. The R% of both third fingers were measured simultaneously before unilateral vibration exposure and 15, 60 and 120 min after the end of each exposure. The R% of both fingers were not affected by the low acceleration vibration (P > 0.10). Exposure to the high acceleration vibration was followed by an unchanged R% of the exposed finger but an increased R% of the non-exposed finger after 15 min (P < 0.05); there was an equal increase of 30%-40% in R% of both fingers after 60 min (P < 0.05). The R% of both fingers had returned to normal after 120 min (P > 0.10). The results would indicate that short-term exposure to vibration induces a transitory hyperreactive central vasoconstrictor drive to the central sympathetic nervous system or circulating agents, which initially was locally counteracted by an induced hyporeactive vasoconstrictor function of local vasomotor mechanisms of the vibration exposed digital arteries. The hyperreactive vasoconstrictor effect demonstrated may contribute to the development of vibration-induced white finger if cumulative exposure time were to be considerably increased.

Vascular toxicity and the mechanism underlying Raynaud's phenomenon in patients treated with cisplatin, vinblastine and bleomycin

The vascular toxicity and the mechanism of Raynaud's phenomenon (RP) were investigated in 32 patients treated with cisplatin, vinblastine, and bleomycin. Sixteen patients had RP and sixteen patients were without finger symptoms. The results were compared with values obtained in 10 male controls. The following postural vasomotor functions were measured: (a) the vasomuscular, non-neurogenic autoregulation, tested by 133xenon flow during elevation of the finger 20 cm; (b) the local veno-arteriolar vasoconstrictor axon reflex, tested similarly by lowering the finger 40 cm; and (c) the central sympathetic vasoconstrictor reflex elicited by central baroreceptors and tested by changing the body posture from supine to sitting upright. The central sympathetic vasoconstrictor reflex was significantly increased in the group of patients with RP and/or cold provocation test positive (n = 16) when compared with the control group (p less than 0.05), and normal in patients without RP (n = 16). The local axon reflex functioned normally, whereas the autoregulation was impaired in both groups of patients compared with the control group (p less than 0.05). The results indicate a hyper-reactivity in the central sympathetic nervous system of the patients with RP, which also may explain their attacks of white fingers. The impaired autoregulation indicates a reduced function of the smooth muscle cells in the terminal arterioles, whereas the greater arterioles seem unaffected, as evidenced by the normal local axon reflex.

Medical audit: assessment of surgical performance in a low volume specialty

We describe a simple technique for auditing one aspect of the activity of a neurosurgical unit--the surgical operations performed. A proforma completed by the surgeon at the time of operation was brought up-to-date on subsequent daily ward rounds. Each week, the medical staff of the unit met to review the data sheets of those patients discharged during the previous seven days. This meeting served to ensure the completeness of the data and to discuss any problems in management before the records were computerized. At the end of the first year, problems which had become apparent in the system were identified and corrected. The revised system involves a comprehensive and prospective audit of relevant clinical information. It has led to the accumulation of a considerable quantity of reliable data and it involves frequent positive feedback which appears to be leading to an improvement in treatment outcome. The system is simple to administer and is economical of time. It should be suitable for any surgical specialty which resembles neurosurgery in dealing with a relatively small volume of major procedures, and it could easily be adapted to audit other aspects of the activity of a unit.