C-Fos brain mapping of global and subunit-specific NMDA receptor antagonists: Relevance for their potential use as antidepressants

Introduction

NMDA receptor antagonists as ketamine represent fast-acting alternatives to monoaminergic-based antidepressants. Major drawbacks of these drugs are psychosis-like states and cortical neurotoxicity, effects correlating with potent activation of the cingulated and retrosplenial cortex. The molecular mechanisms underlying these side-effects have not been deciphered yet.

Aims

We aimed to determine potential molecular components of the NMDA receptor implicated in their psychotomimetic action and investigated whether subunit-specific NMDA receptor antagonists also induce similar neurotoxic changes as ketamine.

Method

To investigate deleterious effects of NMDA receptor antagonists, we used brain mapping with the immediate early gene c-Fos. We analyzed the expression pattern of c-Fos in brain areas responsible for deleterious adverse events, after treatment with ketamine and the NR2B subunit-specific antagonist Ro 25-6981, both in wild-type and knockout mice, lacking either the entire NR2A subunit (NR2A ko mice) or its intracellular C-terminus (NR2A deltaC mice).

Results

In contrast to ketamine (10mg/kg), Ro 25-6981, even at high dosages (50mg/kg) does not induce any c-Fos expression in the cingulated and retrosplenial cortex of wildtype mice. However, Ro 65-2981 evokes, both in NR2A ko mice and NR2A deltaC mice, strong c-Fos expression in these areas.

Conclusions

Our data indicate that blockade of both NR2A and NR2B subunits is necessary to induce deleterious effects specific for ketamine. Deletion of the C-terminus of the NR2A subunit is sufficient to disinhibit, together with pharmacological NR2B blockade, neuronal networks associated with psychosis. Therefore, NR2B antagonists may represent safer alternatives to ketamine as potential antidepressants.

Towards a global barcode library for Lymantria (Lepidoptera: Lymantriinae) tussock moths of biosecurity concern

Background

Detecting and controlling the movements of invasive species, such as insect pests, relies upon rapid and accurate species identification in order to initiate containment procedures by the appropriate authorities. Many species in the tussock moth genus Lymantria are significant forestry pests, including the gypsy moth Lymantria dispar L., and consequently have been a focus for the development of molecular diagnostic tools to assist in identifying species and source populations. In this study we expand the taxonomic and geographic coverage of the DNA barcode reference library, and further test the utility of this diagnostic method, both for species/subspecies assignment and for determination of geographic provenance of populations.

Methodology/Principal Findings

Cytochrome oxidase I (COI) barcodes were obtained from 518 individuals and 36 species of Lymantria, including sequences assembled and generated from previous studies, vouchered material in public collections, and intercepted specimens obtained from surveillance programs in Canada. A maximum likelihood tree was constructed, revealing high bootstrap support for 90% of species clusters. Bayesian species assignment was also tested, and resulted in correct assignment to species and subspecies in all instances. The performance of barcoding was also compared against the commonly employed NB restriction digest system (also based on COI); while the latter is informative for discriminating gypsy moth subspecies, COI barcode sequences provide greater resolution and generality by encompassing a greater number of haplotypes across all Lymantria species, none shared between species.

Conclusions/Significance

This study demonstrates the efficacy of DNA barcodes for diagnosing species of Lymantria and reinforces the view that the approach is an under-utilized resource with substantial potential for biosecurity and surveillance. Biomonitoring agencies currently employing the NB restriction digest system would gather more information by transitioning to the use of DNA barcoding, a change which could be made relatively seamlessly as the same gene region underlies both protocols.

Left ventricular mass and ventricular remodeling among Hispanic subgroups compared with non-Hispanic blacks and whites: MESA (Multi-ethnic Study of Atherosclerosis)

OBJECTIVES

The purpose of this study was to examine the prevalence of left ventricular hypertrophy (LVH) and left ventricular (LV) remodeling patterns within Hispanic subgroups compared with non-Hispanic whites in the MESA (Multi-Ethnic Study of Atherosclerosis).

BACKGROUND

Hispanics are the largest and fastest-growing ethnic minority in the U.S., but there are no data on LVH and LV geometry among Hispanic subgroups.

METHODS

Cardiac magnetic resonance imaging was performed in 4,309 men and women age 45 to 84 years without clinical cardiovascular disease. Hispanics were categorized into subgroups based on self-reported ancestry. LVH was defined as the upper 95th percentile of indexed LV mass in a reference normotensive, nondiabetic, nonobese population, and LV remodeling according to the presence/absence of LVH and abnormal/normal LV mass to LV end-diastolic volume ratio.

RESULTS

Among Hispanic participants, 574 were of Mexican origin, 329 were of Caribbean origin, and 161 were of Central/South American origin. On unadjusted analysis, only Caribbean-origin Hispanics (prevalence ratio = 1.2; 95% confidence interval [CI]: 1.03 to 1.4) had greater prevalence of hypertension than non-Hispanic whites. Hispanic subgroups were more likely to have LVH than non-Hispanic whites after adjustment for hypertension and other covariates (Caribbean-origin Hispanics = odds ratio [OR]: 1.8, 95% CI: 1.1 to 3.0; Mexican-origin Hispanics = OR: 2.2, 95% CI: 1.4 to 3.3; Central/South Americans = OR: 1.5, 95% CI: 0.7 to 3.1). All Hispanic subgroups also had a higher prevalence of concentric and eccentric hypertrophy compared with non-Hispanic whites (p < 0.001).

CONCLUSIONS

Caribbean-origin Hispanics had a higher prevalence of LVH and abnormal LV remodeling compared with non-Hispanic whites. A higher prevalence of LVH and abnormal LV remodeling was also observed among Mexican-origin Hispanics, despite a lower prevalence of hypertension. Differences among Hispanic subgroups regarding LVH and LV remodeling should be taken into account when evaluating cardiovascular risk in this population.

How molecular pathology is changing and will change the therapeutics of patients with follicular cell-derived thyroid cancer: Table 1

Well-differentiated thyroid carcinomas comprise two well-defined histological types: papillary and follicular (PTCs and FTCs, respectively). Despite being derived from the same cell (thyroid follicular cell), these two types of tumour accumulate distinct genetic abnormalities during progression. The molecular pathology of thyroid cancer is now better understood because of our ability to identify RET/PTC rearrangements and BRAF mutations in the aetiopathogenesis of the large majority of PTCs and the high prevalence of RAS mutations and PAX8/PPARγ rearrangements in follicular patterned carcinomas (FTCs and follicular variant of PTCs). This review summarises most of the molecular alterations currently used as targets for new biological treatments and looks at some of the changes that are already occurring or may occur in the treatment of patients with thyroid cancer. For simplicity, the review is divided up according to the major genetic alterations identified in well-differentiated thyroid carcinomas (RET/PTC rearrangements, BRAF mutations, RAS mutations and mitochondrial DNA deletions and mutations) and their respective treatments.

Corin I555(P568) Allele Is Associated With Enhanced Cardiac Hypertrophic Response to Increased Systemic Afterload

Corin activates pro–A-type naturetic peptide and pro–B-type naturetic peptide into biologically active molecules. We recently identified a minor allele in the corin gene defined by 2 highly linked single nucleotide polymorphisms (T555I and Q568P), which was associated with hypertension in blacks. Because of the direct antihypertrophic effects of the natriuretic peptide system, we hypothesized that the minor corin I555(P568) allele would be associated with an enhanced hypertrophic response to pressure overload. The relationship between systolic blood pressure and indexed left ventricular mass, derived from cardiac MRI, was analyzed in the Dallas Heart Study as a function of corin allele status. The Multi-Ethnic Study of Atherosclerosis was used as a validation cohort. All of the analyses were limited to self-identified blacks without treatment for hypertension. In addition, we genotyped 2114 markers highly informative for African ancestry in the Dallas Heart Study and derived a covariate representing African ancestry for multivariate models. In adjusted analysis, the corin I555(P568) allele was an independent predictor of left-ventricular mass in subjects with elevated systolic blood pressure. Linear spline regression analysis confirmed a significant interaction ( P =0.002) between the corin I555(P568) allele and systolic blood pressure as a predictor of left ventricular mass in subjects with systolic blood pressure >120 mm Hg, and this nonlinear interaction was replicated in the Multi-Ethnic Study of Atherosclerosis. In the Dallas Heart Study, the corin I555(P568) allele was also associated with an increased odds for prevalent left ventricular hypertrophy in the presence of untreated hypertension. These data suggest that the corin I555(P568) allele represents a cardiac hypertrophy-sensitizing genetic locus in systemic hypertension.

Clinical efficacy of anti-pneumococcal vaccination in patients with COPD

BACKGROUND

A study was undertaken to evaluate the clinical efficacy of the 23-valent pneumococcal polysaccharide vaccine (PPV) in immunocompetent patients with chronic obstructive pulmonary disease (COPD).

METHODS

A randomised controlled trial was carried out in 596 patients with COPD of mean (SD) age 65.8 (9.7) years, 298 of whom received PPV. The main outcome was radiographically proven community acquired pneumonia (CAP) of pneumococcal or unknown aetiology after a mean period of 979 days (range 20-1454).

RESULTS

There were 58 first episodes of CAP caused by pneumococcus or of unknown aetiology, 25 in the intervention group and 33 in the non-intervention group. Kaplan-Meier survival curves for CAP did not show significant differences between the intervention and non-intervention arms (log rank test = 1.15, p = 0.28) in the whole group of patients. The efficacy of PPV in all patients was 24% (95% CI -24 to 54; p = 0.333). In the subgroup aged <65 years the efficacy of PPV was 76% (95% CI 20 to 93; p = 0.013), while in those with severe functional obstruction (forced expiratory volume in 1 second <40%) it was 48% (95% CI -7 to 80; p = 0.076). In younger patients with severe airflow obstruction the efficacy was 91% (95% CI 35 to 99; p = 0.002). There were only five cases of non-bacteraemic pneumococcal CAP, all in the non-intervention group (log rank test = 5.03; p = 0.025). Multivariate analysis gave a hazard ratio for unknown and pneumococcal CAP in the vaccinated group, adjusted for age, of 0.20 (95% CI 0.06 to 0.68; p = 0.01).

CONCLUSIONS

PPV is effective in preventing CAP in patients with COPD aged less than 65 years and in those with severe airflow obstruction. No differences were found among the other groups of patients with COPD.

Somatic and germline mutation in GRIM-19, a dual function gene involved in mitochondrial metabolism and cell death, is linked to mitochondrion-rich (Hurthle cell) tumours of the thyroid

Oxyphil or Hürthle cell tumours of the thyroid are characterised by their consistent excessive number of mitochondria. A recently discovered gene, GRIM-19 has been found to fulfil two roles within the cell: as a member of the interferon-β and retinoic acid-induced pathway of cell death, and as part of the mitochondrial Complex I assembly. In addition, a gene predisposing to thyroid tumours with cell oxyphilia (TCO) has been mapped to chromosome 19p13.2 in one family. A cluster of genes involved in mitochondrial metabolism occurs in this region; one of these is GRIM-19. We have searched for GRIM-19 mutations in a series of 52 thyroid tumours. Somatic missense mutations in GRIM-19 were detected in three of 20 sporadic Hürthle cell carcinomas. A germline mutation was detected in a Hürthle cell papillary carcinoma arising in a thyroid with multiple Hürthle cell nodules. No mutations were detected in any of the 20 non-Hürthle cell carcinomas tested, nor in any of 96 blood donor samples. In one of the sporadic Hürthle cell papillary carcinomas positive for GRIM-19 mutation, we have also detected a ret/PTC-1 rearrangement. No GRIM-19 mutations were detected in any of the six cases of known familial Hürthle cell tumour tested, so that our results do not support the identification of GRIM-19 as the TCO gene. The GRIM-19 mutations we have detected are the first nuclear gene mutations specific to Hürthle cell tumours to be reported to date; we propose that such mutations can be involved in the genesis of sporadic or familial Hürthle cell tumours through the dual function of GRIM-19 in mitochondrial metabolism and cell death.

Kinetics and dynamic evaluation of specific immunotherapy

Specific immunotherapy (SIT) is frequently used in the treatment of allergic diseases. However, the mechanisms by which SIT achieves clinical improvement remained unclear. We decided to study the in vivo kinetics of this therapy, using a nuclear medicine approach (leukocytes labelled with 99mTc-HMPAO) in patients on maintenance doses of specific immunotherapy with confirmed clinical efficacy.

MATERIAL AND METHODS

We studied 13 allergic patients grouped according to different treatment schedules: subcutaneous aqueous allergenic extract (3 latex and 2 hymenoptera venom), subcutaneous depot extract (2 house dust mite and 2 pollens), subcutaneous modified allergens (2 pollens), sublingual extract (2 house dust mites). The control group included two allergic patients submitted to subcutaneous injections of bacterial extract (1 patient--positive control), and aqueous solution (1 patient). At the same time that the therapeutic allergen was administered subcutaneously, the autologous labelled white cells were injected intravenously in a peripheral vein in the contralateral arm. A thoracic dynamic acquisition of 60 mins, 64x64 matrix, 2 frame/min, in anterior view was performed. Static acquisition for 256x256 matrix, during 5 mins each at 60, 90, 120, 180, 240, 300 and 360 mins after the administration of the radiolabelled leukocytes, in thoracic (anterior and posterior), and abdominal view were performed. During the examination, the local erythema was monitored. A similar procedure was undertaken for Sublingual administration of immunotherapy.

RESULTS

The inflammatory activity at the site of SIT injection (aqueous depot extract) started in the first hour and the increase was time related. For modified allergen extract and sublingual SIT the activity was present since the beginning of the administration. The ascendant lymphatic drainage, which was directed to the homolateral axillary region, to the lymphoid tissue of the upper mediastinum and to the anterior region of the neck began earlier. Thoracic focalisations were present for all the patients, whereas bowel focalisations were only observed for the subcutaneous route of administration. Sublingual SIT did not induce axillary or intestinal inflammatory focalisations, even though the patients had swallowed the allergenic extract. The uptake coefficient in individualized areas corrected to the uptake coefficient background was also studied.

CONCLUSIONS

For the subcutaneous route of administration, except for glutaraldehyde-modified allergen, the local inflammatory activity at the allergenic injection site was significantly higher in depth and was time dependent, maintaining activity even after complete disappearance of the erythema and/or wheal. These results express a prompt inflammatory involvement of the immune system with this allergenic therapy, which was unexpected until now. We also observed differences concerning allergic diseases, the type of allergenic extracts and routes of administration.

Risk factors for intracardiac thrombus in patients with recent ischaemic cerebrovascular events

BACKGROUND

Intracardiac thrombus is a common cause of cardiogenic cerebral ischaemia. Stroke recurrence is high, but thrombus detection with therapeutic intervention can reduce the risk. Accurate detection requires transoesophageal echocardiography (TOE), which is semi-invasive and costly.

OBJECTIVE

To identify risk factors for cardiac thrombus, enabling selection of patients for TOE and initiation of measures to prevent the formation of cardiac thrombus.

METHODS

151 consecutive patients with ischaemic stroke or transient ischaemic attacks (mean age 62 years) underwent TOE for intracardiac thrombus detection within one week of a qualifying event.

RESULTS

Intracardiac thrombus was found in 26% of the patients (70% in the left atrial appendage). Multivariate analysis indicated the following clinical correlates: large stroke, odds ratio (OR) = 2.8 (95% confidence interval, 1.2 to 6.4); symptomatic coronary artery disease, OR = 3.0 (1.2 to 7.4); and ECG evidence of ischaemia, OR = 2.8 (1.1 to 7.7). Neither carotid stenosis >70%, nor stroke location correlated with the presence of thrombus.

CONCLUSIONS

Clinical factors correlate with and appear to be risk factors for cardiac thrombus in patients with recent cerebral ischaemia. These may be used to select appropriate patients for invasive and costly TOE investigation, irrespective of the presence of significant carotid stenosis (>/=70%) or stroke location.

Engraftment syndrome following autologous hematopoietic stem cell transplantation: definition of diagnostic criteria

Engraftment syndrome (ES) is an increasingly reported complication of hematopoietic stem cell transplantation (HSCT). In order to better characterize the clinical criteria for the diagnosis of ES, we retrospectively analyzed 125 autologous HSCT recipients. ES was first defined as the presence of noninfectious fever plus skin rash. Patients with and without these findings were compared (univariate and multivariate analyses) regarding the presence of weight gain, hypoalbuminemia, pulmonary infiltrates, diarrhea, neurological manifestations and jaundice. The variables that are significantly more frequent in patients with fever and skin rash were incorporated in the definition criteria. The final diagnostic criteria were noninfectious fever plus any of the following: skin rash, pulmonary infiltrates or diarrhea. The incidence of ES was 20%. The single risk factor for ES by multivariate analysis was a diagnosis other than Hodgkin's disease (odds ratio 6.17, 95% confidence interval 1.38-27.78). Patients with ES received empirical antifungal therapy more frequently than patients without the syndrome (40 vs 19%, P=0.03), and had a longer duration of hospitalization (P=0.0007). The prospective application of these diagnostic criteria may have a favorable impact on the early diagnosis of the syndrome, with the initiation of corticosteroids and a reduction in the unnecessary use of antimicrobial agents.

Memory and executive functions in aneurysms of the anterior communicating artery

The cognitive outcome of three groups of patients, who had undergone surgery for repair of a single ruptured intracranial aneurysm, was evaluated. We assessed performance on tests of executive functions and memory in a group of 15 patients tested at least 3 months after an aneurysm of the anterior communicating artery (ACoA) and in a group of 12 patients tested in the first month after the same pathology. Acute patients were more impaired overall than chronic ones, but the two groups significantly differed on two executive and one memory test. The performance of the ACoA patients was also compared to the performance of a group of 10 patients who had undergone surgery for an aneurysm located on the posterior communicating artery (PCoA) at least 3 months before the examination. Chronic ACoA and PCoA patients significantly differed in two memory and in two executive tests performance, with posterior patients being more impaired than anterior. An unexpected finding was the impairment of semantic memory in ACoA patients.

Mortality and prognostic factors in Spanish patients with systemic sclerosis

OBJECTIVE

To determine survival and mortality in a cohort of Spanish patients with scleroderma (systemic sclerosis, SSc) and to analyse whether survival is influenced by demographic, clinical or immunological variables or the extent of skin involvement.

METHODS

The study included 79 patients diagnosed with SSc and taking part in a study to determine the extent of sclerosis, visceral involvement and immunological alterations. We studied the number of observed and expected deaths (the expected number being based on age- and sex-specific rates in the background population) and derived standardized mortality ratios with their 95% confidence intervals (CI). Cumulative survival after onset of the first symptom was estimated according to the Kaplan-Meier method. The Cox method was used to identify the prognostic factors.

RESULTS

The mortality rate was 0.0249 deaths per person-year. Survival at 15 yr was 0.62 (95% CI 0.410-0.778). The standardized mortality ratio was 429.4% (95% CI 222-750). On crude analysis, lung involvement [forced vital capacity (FVC) <70%, pulmonary hypertension], SSc renal crisis, an active capillaroscopic pattern, pericardial effusion and age over 60 yr at diagnosis were associated with shorter survival. On multivariate analysis, only age at diagnosis over 60 yr, FVC <70% and SSc renal crisis were independent prognostic factors.

CONCLUSIONS

The mortality rate associated with SSc showed a four-fold increase compared with the background population. Lung involvement and sclerodermal renal crisis were found to be independently associated with reduced survival.

Echocardiographic and pathologic characteristics of primary cardiac tumors: a study of 149 cases

To investigate the characteristics and pathological features of primary cardiac tumors and to evaluate the diagnostic sensitivity of echocardiography in primary cardiac tumors, all pathologic and echocardiographic records at the Chinese PLA general hospital and its satellite hospitals between January 1st, 1990 and January 1st, 2000 were reviewed to identify patients with a confirmed diagnosis of primary cardiac tumors. A total of 149 patients who had complete echocardiographic records and who were diagnosed with primary cardiac tumors were included in the study. Pathologic and echocardiographic records were reviewed retrospectively to evaluate the presence, location and histologic type of the tumors. The majority (n=118, 79.2%) of cases had been diagnosed with benign tumors. Myxoma was the most common histologic type accounting for 50.0% of total cardiac tumors. Lipoma was the second most common type of benign tumor. Among cases with malignant tumors (n=31, 20.8%), unclassified sarcoma (n=7), angiosarcoma (n=6) and rhabdomyosarcoma (n=6) were the common histologic types of primary malignant tumor. Non-myxomatous benign tumors were more likely to have occurred in the ventricle than myxomas (17/43, 39.5% vs. 7/75, 9.3%; P=0.00). The proportion of pericardium involvement in the malignant tumors (8/31, 25.8%) was significantly higher than that in the myxomas (0/75, 0%; P=0.00) and non-myxomas (2/43, 4.7%; P=0.01). The diagnostic sensitivity of transthoracic and transesophageal echocardiography was 93.3% (139/149) and 96.8% (30/31), respectively. The study, using a relatively large sample, confirms that myxoma was the most common primary cardiac tumor. The locations of tumor involvement varied by types of tumor. Echocardiography may be a useful tool for early diagnosis of primary cardiac tumors.

Endocrine disorder as the only sign of chronic "non-hypertensive" hydrocephalus

Three cases of "non-hypertensive" chronic hydrocephalus, 2 of which associated with early puberty and 1 with primary amenorrhea, are reported. Hormonal secretion deficiencies were confirmed by laboratory investigations. Only 1 of the 3 patients was surgically treated with a shunting device.

Risk factors for progression of aortic atheroma in stroke and transient ischemic attack patients

BACKGROUND AND PURPOSE

Aortic atheroma is an independent risk factor for stroke and undergoes temporal progression. Clinical and risk factor associations of such progression are unknown. Hyperhomocysteinemia has been linked with atherosclerosis, including that in the cerebral vasculature. This study investigated associations between elevated homocysteine levels and other stroke vascular risk factors and the risk of aortic atheroma progression in patients with cerebrovascular disease.

METHODS

Fifty-seven stroke and 21 transient ischemic attack patients underwent multiplanar transesophageal echocardiograms within 1 month of symptom onset and again at 9 months. Aortic atheroma was graded and stratified by use of existing criteria. Stroke risk factors; use of anticoagulant, antiplatelet, and hypolipidemic drugs; and clinical and etiological subtypes of stroke were recorded and compared in patients stratified for the presence or absence of aortic atheroma progression.

RESULTS

Of the 78, 29 (37%) progressed, 32 (41%) remained unchanged, and 17 (22%) regressed. Progression was most marked at the aortic arch (P=0.005), followed by the ascending segment (P<0.04). In nearly two thirds of the patients in whom aortic atheroma remained unchanged over 9 months, no atheroma was evident on baseline transesophageal echocardiogram. Only homocysteine levels > or =14.0 micromol/L (P=0.02), total anterior cerebral infarct (P=0.02), and large-artery atherosclerosis (P=0.005) significantly correlated with progression.

CONCLUSIONS

Among vascular risk factors, elevated homocysteine levels are associated with aortic atheroma progression. Stroke and transient ischemic attack patients with aortic atheroma should undergo assessment of homocysteine levels, which, if elevated, may be treated with vitamins in an effort to arrest aortic atheroma progression.

Specific haplotypes of the RET proto-oncogene are over-represented in patients with sporadic papillary thyroid carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC), which may be sporadic (95%) or familial (5%), has a prevalence adjusted for age in the general population of 1:100 000. Somatic rearrangements of the RET proto-oncogene are present in up to 66% of sporadic tumours, while they are rarely found in familial cases.

PURPOSE

In order to determine if some variants of this gene, or a combination of them, might predispose to PTC, we looked for an association of RET haplotype(s) in PTC cases and in controls from four countries matched for sex, age, and population.

METHODS

Four single nucleotide polymorphisms (SNPs) across the RET coding sequence were typed and haplotype frequencies were estimated. Genotype and haplotype distributions were compared among these cases and controls.

RESULTS

Ten haplotypes were observed, the seven most frequent of which have been previously described in sporadic Hirschsprung patients and controls. The single locus analyses suggested association of exon 2 and exon 13 SNPs with sporadic PTC. The haplotype analysis showed over-representation of one haplotype in French and Italian sporadic PTC, whereas a different haplotype was significantly under-represented in French familial PTC.

CONCLUSIONS

Our data suggest that some variants of RET and some specific haplotypes may act as low penetrance alleles in the predisposition to PTC.

Morphologic capillary changes and manifestations of connective tissue diseases in patients with primary biliary cirrhosis

The objective of this study was to investigate the presence of nailfold capillary abnormalities and extrahepatic signs of connective tissue disease in patients with primary biliary cirrhosis (PBC), as compared to patients with other chronic liver diseases. We evaluated 22 patients with PBC and 15 patients with other chronic liver diseases as a control group. Nailfold capillaroscopy was performed by two observers blinded to clinical findings using a Wild M3 stereomicroscope with an Intralux 5000 Volpi cold light lamp. We detected nailfold capillary abnormalities in 20 out of 22 (91%) PBC patients. Twelve of these 20 patients (54%) showed capillary alterations characteristic of systemic sclerosis. In the control group only two out of 15 patients (13%) presented alterations and in both cases they were a non-specific type. The presence of nailfold capillary abnormalities was significantly greater in PBC patients than in the control group (P < 0.001). Eleven out of the 22 PBC patients (50%) had extrahepatic signs of connective tissue disease and most of them were related to systemic sclerosis; patients with other chronic liver diseases did not present rheumatic manifestations (P < 0.001). In PBC patients there was a significant association between systemic sclerosis capillary pattern and rheumatic manifestations (P < 0.03). The high prevalence of nailfold capillary abnormalities characteristic of systemic sclerosis in patients with PBC and the correlation with sclerodermal manifestations suggests that this capillaroscopic finding could be a useful indicator to investigate rheumatic manifestations in these patients.

Echocardiographic and pathological characteristics of cardiac metastasis in patients with lymphoma

The purposes of this study were to investigate the patterns of lymphoma involvement in the heart and to correlate pathologic findings in the heart at autopsy with echocardiographic presentation prior to death in patients with malignant lymphoma. Lymphoma patients with complete echocardiographic records prior to death and conformed cardiac metastasis at autopsy were included in the study. Echocardiographic records were reviewed retrospectively. Pathological diagnoses were compared with echocardiographic findings using Fisher's exact test. Twenty-nine patients aged 19-71 (mean +/- SD, 51.5+/-12.7) years were included in the study. Among them 17 (58.6%) were male. There were 6 cases (20.7%) with Hodgkin's disease and 23 (79.3%) cases with non-Hodgkin's lymphoma. Twenty-two (75.9%) cases were diagnosed with cardiac metastases at autopsy by gross appearance of their hearts. The most common (41.4%) site of metastatic involvement was the pericardium. The frequency of tumor on the valves was significantly lower than in the chambers and on other parts of the heart (6.9% versus 93.1%). Metastatic masses in right heart were found in 8 (8/23, 34.8%) non-Hodgkin's lymphoma cases, which was higher than that in Hodgkin's lymphoma cases (0/6, 0%; p=0.15). The frequency of high-grade non-Hodgkin's disease metastasizing to the right ventricle was significantly higher than that for the other kinds of lymphoma (3/7, 42.9% versus 0/22, 0%; p=0.01). Sensitivity of echocardiographic examination to detect cardiac metastasis was 75.9%. Echocardiography has been shown to be a sensitive method for the diagnosis of cardiac involvement in the patients with lymphoma. Patterns of cardiac involvement vary by the types of lymphoma, suggesting that different pathologic types of lymphoma may have different mechanisms of metastasis to the heart.

Echocardiographic and pathological characteristics of cardiac metastasis in patients with lymphoma

The purposes of this study were to investigate the patterns of lymphoma involvement in the heart and to correlate pathologic findings in the heart at autopsy with echocardiographic presentation prior to death in patients with malignant lymphoma. Lymphoma patients with complete echocardiographic records prior to death and conformed cardiac metastasis at autopsy were included in the study. Echocardiographic records were reviewed retrospectively. Pathological diagnoses were compared with echocardiographic findings using Fisher's exact test. Twenty-nine patients aged 19-71 (mean +/- SD, 51.5+/-12.7) years were included in the study. Among them 17 (58.6%) were male. There were 6 cases (20.7%) with Hodgkin's disease and 23 (79.3%) cases with non-Hodgkin's lymphoma. Twenty-two (75.9%) cases were diagnosed with cardiac metastases at autopsy by gross appearance of their hearts. The most common (41.4%) site of metastatic involvement was the pericardium. The frequency of tumor on the valves was significantly lower than in the chambers and on other parts of the heart (6.9% versus 93.1%). Metastatic masses in right heart were found in 8 (8/23, 34.8%) non-Hodgkin's lymphoma cases, which was higher than that in Hodgkin's lymphoma cases (0/6, 0%; p=0.15). The frequency of high-grade non-Hodgkin's disease metastasizing to the right ventricle was significantly higher than that for the other kinds of lymphoma (3/7, 42.9% versus 0/22, 0%; p=0.01). Sensitivity of echocardiographic examination to detect cardiac metastasis was 75.9%. Echocardiography has been shown to be a sensitive method for the diagnosis of cardiac involvement in the patients with lymphoma. Patterns of cardiac involvement vary by the types of lymphoma, suggesting that different pathologic types of lymphoma may have different mechanisms of metastasis to the heart.

Mini-sternotomy for the treatment of aortic valve lesions

OBJECTIVE

To compare inverted-L mini-sternotomy performed above the sternal furcula with conventional sternotomy in patients with aortic valve diseases who undergo surgical treatment.

METHODS

We operated upon 30 patients who had aortic valve lesions that had clinical and hemodynamic findings. All patients underwent inverted-L sternotomy, which extended from above the manubrium of the sternum to the 3rd right intercostal space, without opening the pleural cavity. Their ages ranged from 32 to 76 years, and 18 were males and 12 were females. We used negative pressure in a venous 1/4-inch cannula, and the patients were maintained in Trendelemburg's position. Twenty-seven patients received bioprostheses with diameters ranging from 23 to 29mm. Three patients underwent only removal of the calcifications of the aortic valve leaflets and aortic commissurotomy.

RESULTS

The mean duration of anoxic cardiac arrest was 63.11min. Access was considered good in all patients. One death was due to pulmonary and renal problems not related to the incision. All patients had a better recovery in the intensive care unit, got out of bed sooner, coughed more easily, and performed prophylactic physiotherapeutic maneuvers for respiratory problems more easily and with less pain in the incision. Early ambulation was more easily carried out by all patients.

CONCLUSION

Mini-sternotomy proved to be better than the conventional sternotomy because it provided more comfort for the patients in the early postoperative period, with less pain and greater desire for early ambulation and all its inherent advantages.

Interactions between calcium, phosphate, and albumin on the surface of titanium

The deposition of calcium phosphate on chemically polished commercially pure titanium immersed in Hank's balanced salt solution (HBSS) with bovine serum albumin (BSA) (concentrations 0 and 4 mg/mL) has been investigated. Electrochemical techniques, 125I labeling of albumin, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were used. A tricalcium phosphate layer with a thickness of ca. 1 microm was formed for periods of immersion in HBSS ranging between 1 and 2 weeks. A concentration of 4 mg/mL of BSA prevented its formation, even for periods as long as 1 month. In the absence of BSA, the electrochemical behavior of titanium specimens was significantly affected by the length of immersion time, reflecting the changes that slowly occur on their surface. In the presence of BSA, the surfaces maintained most of their original electrochemical activity. Surface studies have shown that calcium and phosphate become incorporated in the surface at very early stages of immersion. Albumin, which was rapidly adsorbed on titanium, was slowly desorbed when titanium was placed in HBSS. Protein and phosphate may coexist on the same surface, but initially adsorbed albumin molecules prevent the precipitation of a thick layer of tricalcium phosphate.

Frequency and predictors of stroke death in 5,888 participants in the Cardiovascular Health Study

BACKGROUND

Few population-based studies have examined in detail issues of stroke-related deaths in elderly people.

METHODS

Participants in the Cardiovascular Health Study (CHS) are 65 years of age or older, have had extensive baseline evaluations, and have been followed-up for fatal and nonfatal cardiovascular and cerebrovascular disease outcomes. Investigators adjudicated these outcomes and classified strokes by types and subtypes.

RESULTS

Over 7 years, 1,310 (22.2%) of 5,888 participants died, and 455 (7.7%) experienced incident stroke. For the 5,888, stroke mortality was 3.2 per 1,000 person-years. For the 455, it was 36.1 per 1,000 person-years, with the most lethal type being hemorrhagic and the ischemic subtype being cardioembolic. After controlling for age and stroke type, the only other independent predictor of death after any stroke was poor performance on a timed walk measured before the incident stroke. Considering only ischemic stroke, the independent predictors of death were African American race and poor performance on timed walk.

CONCLUSION

In CHS, death attributable to stroke is common. As in other studies, the most lethal stroke type was hemorrhagic, and ischemic stroke subtype, cardioembolic. Slow walking, possibly a measure of frailty, was associated with an increased risk of death of stroke. Finally, African Americans faced a greater risk of death than others after an ischemic stroke.

Orthostatic Hypotension in the Elderly: Contributions of Impaired LV Filling and Altered Sympathovagal Balance

Orthostatic hypotension, which occurs in 5%-18% of the elderly, may contribute to age-related disability. While autonomic dysfunction and alterations of cardiac structure and function likely to impair postural maintenance of blood pressure are common in the elderly, these have not been jointly studied in large cohorts. The authors evaluated the association of orthostatic hypotension with echocardiographic measures of cardiac structure and function, and with autonomic function determined by analysis of heart rate variability, in a large population of community-dwelling elderly. A total of 5201 men and women, aged 65-100 years and living in four geographically separate communities, were recruited from Medicare eligibility lists. In this prospective, observational cohort study, measurements included clinical questionnaires, standing and supine blood pressures, mini-glucose tolerance testing, echocardiography, and 24-hour Holter recording for assessment of heart rate variability. Orthostatic hypotension, defined as a decrease in standing systolic blood pressure of 20 mm Hg or more, was positively associated in bivariate analyses with left ventricular wall thickness, peak velocity of late diastolic filling, vagal tone on heart rate variability analysis, supine systolic pressure, supine diastolic pressure, age, and diabetes, and inversely associated with body weight. After statistical adjustment for the presence of myocardial infarction, stroke, and use of antihypertensive medication, the associations were maintained, and a previous trend toward an association with decreased left ventricular cavity size became statistically significant. The data suggest that in elderly, community-based individuals, orthostatic hypotension is associated with increased blood pressure and decreased weight; it possibly acts mechanistically via altered sympathovagal balance, increased left ventricular wall thickness, decreased left ventricular preload, and alterations of left ventricular diastolic filling. (c) 2000 by CVRR, Inc.

Visualization and temporal/spatial characterization of cardiac radiofrequency ablation lesions using magnetic resonance imaging

BACKGROUND

The purpose of this study was to describe a system and method for creating, visualizing, and monitoring cardiac radiofrequency ablation (RFA) therapy during magnetic resonance imaging (MRI).

METHODS AND RESULTS

RFA was performed in the right ventricular apex of 6 healthy mongrel dogs with a custom 7F nonmagnetic ablation catheter (4-mm electrode) in a newly developed real-time interactive cardiac MRI system. Catheters were positioned to intracardiac targets by use of an MRI fluoroscopy sequence, and ablated tissue was imaged with T2-weighted fast spin-echo and contrast-enhanced T1-weighted gradient-echo sequences. Lesion size by MRI was determined and compared with measurements at gross and histopathological examination. Ablated areas of myocardium appeared as hyperintense regions directly adjacent to the catheter tip and could be detected 2 minutes after RF delivery. Lesions reached maximum size approximately 5 minutes after ablation, whereas lesion signal intensity increased linearly with time but then reached a plateau at 12.2+/-2.1 minutes. Lesion size by MR correlated well with actual postmortem lesion size and histological necrosis area (55.4+/-7.2 versus 49.7+/-5.9 mm(2), r=0.958, P<0.05).

CONCLUSIONS

RFA can be performed in vivo in a new real-time interactive cardiac MRI system. The spatial and temporal extent of cardiac lesions can be visualized and monitored by T2- and T1-weighted imaging, and MRI lesion size agrees well with actual postmortem lesion size. MRI-guided RFA may be a useful approach to help facilitate anatomic lesion placement and to provide insight into the biophysical effects of new ablation techniques and technologies.

Sequential group trial to determine gastrointestinal site of absorption and systemic exposure of azathioprine

Azathioprine (AZA) is used in the treatment of patients with refractory inflammatory bowel disease; however, its use is limited because of systemic toxicity associated with long-term use. Ileocecal delivery of AZA might be advantageous if local intestinal therapeutic effects could be provided with decreased systemic side effects. Decreased cecal systemic absorption would allow higher dosages of AZA to be administered. A two-phase study was performed to compare the systemic exposure of AZA and 6-mercaptopurine (6-MP) following administration of AZA into the stomach, jejunum, and cecum and to compare the systemic exposure to AZA and 6-MP following administration of three different dosages of AZA into the cecum. In phase I, six healthy male volunteers received three 50 mg sequential doses of AZA via an oral tube directly placed into the stomach, jejunum, and cecum, respectively. In phase II, six healthy male volunteers received three different dosages (50, 300, 600 mg of AZA) into the cecum. Plasma concentrations of AZA and 6-MP at various times were quantified and area under the plasma concentration-time curve (AUC) and mean residence time (MRT) were determined. No significant differences in the AUC of AZA were seen at the different sites. The AUC of 6-MP following administration of AZA into the jejunum (67.0 +/- 30.1 ng x hr/ml) was higher compared to the stomach (39.9 +/- 38.1 ng/hr/ml) and cecum (29.2 +/- 10.9 ng x hr/ml). Jejunal absorption was 68% higher than absorption from the stomach and 129% higher than that of the cecum. Gastric absorption was 27% higher than that of the cecum. Increased dosages given into the cecum resulted in increased AUCs of AZA and 6-MP. The AUCs of AZA following 50, 300, and 600 mg dosages were 16.9 +/- 7.4, 52.3 +/- 67.2, and 132 +/- 151 ng x hr/ml, respectively, and the AUCs of 6-MP were 22.2 +/- 14.9, 63.4 +/- 50.6, and 104 +/- 115 ng x hr/ml, respectively. Systemic exposure to 6-MP is reduced following administration of AZA into the cecum, most likely secondary to reduced absorption of 6-MP from the colon. Higher dosages of AZA presented to the cecum do result in increased systemic absorption, but may still allow more drug to be administered with less toxicity than the same dose received orally.

The Charcot foot

AIMS

To review the clinical manifestations of the Charcot foot in diabetes mellitus, with particular reference to theories concerning aetiology.

METHODS

Systematic review of the published literature, searching for the keywords 'Charcot', 'foot and diabetes' and 'neuropathy' on Medline, as well as by examination of the references in recent published reviews.

CONCLUSIONS

The Charcot foot of diabetes mellitus is a common problem, and yet is not widely recognized by non-specialists. The failure of professionals to identify the condition in its early phases is probably largely responsible for the gross deformity which follows continued weight-bearing. The condition is confined to those with severe peripheral neuropathy. It is thought to result from three factors: motor neuropathy leading to the development of abnormal forces within the foot, subsequent disorganization of the foot as a result of associated osteopenia and progressive destruction from continued weight-bearing, enabled by reduced pain sensation. The cause of the osteopenia is not known, but it is associated with increased bone blood flow, which may be mainly the result of loss of sympathetic innervation. The importance of increased limb blood flow in the pathogenesis of the Charcot foot has been recognized for over a century. Paradoxically, the increased flow is associated with evidence of macrovascular disease, in that the prevalence of vascular calcification of pedal vessels approaches 90%. After an interval of many months, the condition tends to evolve: the increased blood flow lessens, the osteopenia is reduced and the disorganized bones become sclerotic. This tendency for the condition to evolve remains unexplained, since it would not be expected if the condition was caused solely by progressive denervation. As a result, it is suggested that another factor may be involved in the pathogenesis of the Charcot foot: an abnormal vasomotor reflex, analogous to reflex sympathetic dystrophy, occurring against a background of severe peripheral neuropathy. The resolution of the condition occurs because it is the reflex component of the hyperaemia which proves self-limiting.