The Natural History of Atrial Functional Mitral Regurgitation

BACKGROUND

The natural history of moderate/severe atrial functional mitral regurgitation (AFMR) is unknown.

OBJECTIVES

The authors sought to study the incidence of left ventricular (LV) systolic dysfunction (LVSD), progression or regression of ≥mild-moderate AFMR, and impact on mortality.

METHODS

Adults with left atrial (LA) volume index ≥40 mL/m2, ≥mild-moderate AFMR, and follow-up echocardiogram were followed for incident LVSD (ejection fraction <50% and ≥10% lower than baseline), progression of mild-moderate/moderate AFMR to severe, and persistent regression of AFMR to no/trivial. Relation of AFMR progression or regression as time-dependent covariates with all-cause mortality was studied. Incidence of LVSD was compared with patients with no/mild AFMR matched on age, sex, comorbidities and ejection fraction. Patients were followed until mitral intervention, myocardial infarction, or last follow-up.

RESULTS

A total of 635 patients (median age 75 years, 51% female, 96% mild-moderate/moderate AFMR, 4% severe AFMR) were included. Over a median 2.2 years (Q1-Q3: 1.0-4.3 years), incidence rates per 100 person-years were 3.2 for LVSD (P = 0.52 vs patients with no/mild AFMR), 1.9 for progression of AFMR, and 3.9 for regression. Female sex and larger LA volume index were independently associated with progression, whereas younger age, male sex, absent atrial fibrillation, and higher LA emptying fraction were independently associated with regression. Neither AFMR progression nor regression was independently associated with mortality. Instead, independent risk factors for mortality included older age, concentric LV geometry, and higher estimated LV filling and pulmonary pressures.

CONCLUSIONS

In patients with predominantly mild-moderate/moderate AFMR, regression of MR was more common than progression, but neither was associated with mortality. Instead, diastolic function abnormalities were more important. Over a median 2-year follow-up, LVSD risk was not increased.

Impact on Kidney Function and Medium-Term Outcomes of Transcatheter Aortic Valve Replacement in Patients With Chronic Kidney Disease

Transcatheter aortic valve replacement (TAVR) is now widely approved for the treatment of aortic stenosis, regardless of the patients' surgical risk. However, the outcomes of TAVR and their determinants in patients with chronic kidney disease (CKD) beyond 1 year of follow-up are unknown. We aimed to assess the medium-term outcomes of TAVR in CKD, develop a risk score to estimate the 2-year mortality in patients with CKD, and evaluate the changes in kidney function at discharge after TAVR. Adults who underwent TAVR were retrospectively identified. The CKD stage was determined using the Chronic Kidney Disease Epidemiology 2021 creatinine formula. Improved kidney function was defined as post-TAVR creatinine ≤50% of pre-TAVR creatinine or decrease in creatinine of ≥0.3 mg/100 ml compared with pre-TAVR creatinine. Overall, 1,523 patients (median age 82 years; 59% men; 735 with CKD stage II or less, 661 with CKD III, 83 with CKD IV, and 44 with CKD V [of whom 40 were on dialysis]) were included. The all-cause mortality was higher in CKD stages IV and V on the multivariable analysis (p <0.001) at median follow-up of 2.9 (interquartile range 2.0 to 4.2) years. Moderate or severe tricuspid regurgitation, anemia, right ventricular systolic pressure >40 mm Hg and CKD stages IV and V were independent predictors of 2-year mortality and were used to develop a risk score. At hospital discharge, persisting acute kidney injury after TAVR occurred in 88 of 1,466 patients (6%), whereas improved kidney function occurred in 170 of 1,466 patients (12%). In conclusion, CKD stage was an independent determinant of mortality beyond 2 years after TAVR. Kidney function was more likely to improve than worsen at the time of hospital discharge after TAVR.

Prevalence and incidence of diastolic dysfunction in atrial fibrillation: clinical implications

BACKGROUND AND AIMS

Atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) are intimately associated disorders; HFpEF may be overlooked in AF when symptoms are simply attributed to dysrhythmia, and incident AF may identify patients at risk for developing diastolic dysfunction (DD). This study aimed to investigate the prevalence and incidence of DD in patients with new-onset AF compared with sinus rhythm (SR).

METHODS

Adults with new-onset AF (n = 1747) or SR (n = 29 623) and no structural heart disease were identified. Propensity score matching was performed (1:3 ratio) between AF and SR based on age, sex, body mass index, and comorbidities. Severe DD (SDD) was defined by ≥3/four abnormal parameters (medial e', medial E/e', tricuspid regurgitation velocity, and left atrial volume index) and ≥moderate DD (>MDD) by ≥2/4. Annualized changes in DD indices were determined.

RESULTS

New-onset AF was independently associated with SDD (8% vs. 3%) and ≥MDD (25% vs. 16%); 62% of patients with AF had high-risk H2FPEF scores, and 5% had clinically recognized HFpEF. Over a median follow-up of 3.2 (interquartile range 1.6-5.8) years, DD progressed two-four-fold more rapidly in those with new-onset AF (P < .001 for all). The risk for incident DD was increased in new-onset AF [hazard ratio (95% confidence interval) 2.69 (2.19-3.32) for SDD and 1.73 (1.49-2.02) for ≥MDD].

CONCLUSIONS

Patients with new-onset AF display high-risk features for HFpEF at diagnosis, emphasizing the importance of evaluating for HFpEF among symptomatic patients with AF. Patients with new-onset AF have accelerated progression in DD over time, which may identify patients with preclinical HFpEF, where preventive therapies may be tested.

Incidence, risk factors, and outcomes of atrial functional mitral regurgitation in patients with atrial fibrillation or sinus rhythm

AIMS

Atrial functional mitral regurgitation (AFMR) has been associated with atrial fibrillation (AF) and heart failure with preserved ejection fraction. However, data on incident AFMR are scarce. We aimed to study the incidence, risk factors, and clinical significance of AFMR in AF or sinus rhythm (SR).

METHODS AND RESULTS

Adults with new diagnosis of AF and adults in SR were identified. Patients with >mild MR at baseline, primary mitral disease, cardiomyopathy, left-sided valve disease, previous cardiac surgery, or with no follow-up echocardiogram were excluded. Diastolic dysfunction (DD) was indicated by ≥2/4 abnormal diastolic function parameters [mitral medial e', mitral medial E/e', tricuspid regurgitation velocity, left atrial volume index (LAVI)]. Overall, 1747 patients with AF and 29 623 in SR were included. Incidence rate of >mild AFMR was 2.6 per 100 person-year in new-onset AF and 0.7 per 100 person-year in SR, P < 0.001. AF remained associated with AFMR in a propensity score-matched analysis based on age, sex, and comorbidities between AF and SR [hazard ratio: 3.80 (95% confidence interval 3.04-4.76)]. Independent risk factors associated with incident AFMR were age ≥65 years, female sex, LAVI, and DD in both AF and SR, in addition to rate (vs. rhythm) control in AF. Incident AFMR was independently associated with all-cause death in both groups (both P < 0.001).

CONCLUSIONS

AF conferred a three-fold increase in the risk of incident AFMR. DD, older age, left atrial size, and female sex were independent risk factors in both SR and AF, while rhythm control was protective. AFMR was universally associated with worse mortality.

Medium-Term Outcomes of the Different Antithrombotic Regimens After Transcatheter Aortic Valve Implantation

Bioprosthetic valve thrombosis is associated with accelerated bioprosthesis degeneration and valve re-replacement. Whether 3-month warfarin use after transcatheter aortic valve implantation (TAVI) protects against such consequences is unknown. We aimed to investigate if 3-month warfarin treatment after TAVI is associated with better outcomes than dual antiplatelet therapy (DAPT) and single antiplatelet therapy (SAPT) at medium-term follow-up. Adults who underwent TAVI were identified retrospectively (n = 1,501) and classified into warfarin, DAPT, and SAPT groups based on antithrombotic regimen received. Patients with atrial fibrillation were excluded. Outcomes and valve hemodynamics were compared between the groups. Annualized change from baseline in mean gradients and effective orifice area at last follow-up echocardiography was calculated. Overall, 844 patients were included (mean age: 80 ± 9 years, 43% women; 633 receiving warfarin, 164 DAPT, and 47 SAPT). Median time to follow-up was 2.5 (interquartile range 1.2 to 3.9) years. There were no differences in the adjusted outcome end points of ischemic stroke, death, valve re-replacement/intervention, structural valve degeneration, or their composite end point at follow-up. Annualized change in aortic valve area was significantly higher in DAPT (-0.11 [0.19] cm²/year) than warfarin (-0.06 [0.25] cm²/y, p = 0.03), but annualized change in mean gradients was not different (p >0.05). In conclusion, antithrombotic regimen, including warfarin, after TAVI was associated with marginally lower decrease in aortic valve area but no difference in medium-term clinical outcomes compared with DAPT and SAPT.

Video gaming enhances psychomotor skills but not visuospatial and perceptual abilities in surgical trainees

INTRODUCTION

There is considerable interest in the identification and assessment of underlying aptitudes or innate abilities that could potentially predict excellence in the technical aspects of operating. However, before the assessment of innate abilities is introduced for high-stakes assessment (such as competitive selection into surgical training programs), it is essential to determine that these abilities are stable and unchanging and are not influenced by other factors, such as the use of video games. The aim of this study was to investigate whether experience playing video games will predict psychomotor performance on a laparoscopic simulator or scores on tests of visuospatial and perceptual abilities, and to examine the correlation, if any, between these innate abilities.

METHODS

Institutional ethical approval was obtained. Thirty-eight undergraduate medical students with no previous surgical experience were recruited. All participants completed a self-reported questionnaire that asked them to detail their video game experience. They then underwent assessment of their psychomotor, visuospatial, and perceptual abilities using previously validated tests. The results were analyzed using independent samples t tests to compare means and linear regression curves for subsequent analysis.

RESULTS

Students who played video games for at least 7 hours per week demonstrated significantly better psychomotor skills than students who did not play video games regularly. However, there was no difference on measures of visuospatial and perceptual abilities. There was no correlation between psychomotor tests and visuospatial or perceptual tests.

CONCLUSIONS

Regular video gaming correlates positively with psychomotor ability, but it does not seem to influence visuospatial or perceptual ability. This study suggests that video game experience might be beneficial to a future career in surgery. It also suggests that relevant surgical skills may be gained usefully outside the operating room in activities that are not related to surgery.

The management of rectal cancer in Ireland in 2007--room for improvement?

INTRODUCTION

Effective management of rectal cancer relies on accurate pre-operative assessment, surgical technical excellence and integrated neoadjuvant and adjuvant chemo and/or radiotherapy. The aim of this study was to examine the management of rectal cancer in Ireland.

METHODS

This was a retrospective chart review. All cases of rectal cancer (15 cm or less from the anal verge) diagnosed in Ireland in the year 2007 were included in the audit.

RESULTS

In total data for 585 patients were included, under the care of 87 consultant surgeons operating in 48 hospitals. Only data recorded in medical charts were included. Pre-operative investigations were less utilised than recommended by current guidelines and consequently many cancers were inadequately staged. In total 52.5% of cases were discussed at a multi-disciplinary meeting. Overall, 88% of the patients had surgery, and the 30-day mortality rate was 1.7%. The quality of post-operative pathology reporting was variable, with adequacy of total mesorectal excision status unclear or unknown in 74% of cases. Cases were managed in a large number of centres, and in lower volume centres (<5 cases per annum) patients appeared to be less adequately investigated.

CONCLUSION

This study gives a snapshot of recent practice in the management of rectal cancer in Ireland but is of necessity limited as the audit was retrospective and long term outcomes have not been assessed. In 2007 rectal cancer was managed in a large number of centres and best practice was frequently not adhered to. The impending centralisation of cancer services is likely to impact on the management of rectal cancer in Ireland.

Coping with stress in surgery: the difficulty of measuring non-technical skills

BACKGROUND

Non-technical skills are relevant to surgical performance but are difficult to quantify. The aim of this study was to investigate the relationship between self-efficacy, which is a measure of stress-coping ability, and surgical performance.

METHODS

Two hundred and sixteen basic surgical trainees were assessed on their performance of three bench model-type open and laparoscopic surgical tasks. They also completed a 10-item General Self-Efficacy (GSE) questionnaire to assess their stress-coping abilities. Their assessment scores were correlated with the GSE scores.

RESULTS

The mean GSE score of 31.39 was higher than the recorded population norms. There was no significant correlation between GSE and surgical performance for open or laparoscopic tasks.

CONCLUSION

Junior surgical trainees have high self-belief scores, but these abilities are difficult to measure and quantify. More refined methods may be necessary to measure non-technical skills relevant to surgery.

Objective assessment of surgical performance and its impact on a national selection programme of candidates for higher surgical training in plastic surgery

OBJECTIVE

The objective of this study was to develop and validate a transparent, fair and objective assessment programme for the selection of surgical trainees into higher surgical training (HST) in plastic surgery in the Republic of Ireland.

METHODS

Thirty-four individuals applied for HST in plastic surgery at the Royal College of Surgeons in Ireland (RCSI) in the academic years 2005-2006 and 2006-2007. Eighteen were short-listed for interview and further assessment. All applicants were required to report on their undergraduate educational performance and their postgraduate professional development. Short-listed applicants completed validated objective assessment simulations of surgical skills, an interview and assessment of their suitability for a career in surgery.

RESULTS

When applicants' short-listing scores were combined with their interview scores and assessment of their suitability for a career in surgery, individuals who were selected for HST in plastic surgery performed significantly better than those who were not (P<0.002). However, when the assessment of technical skills scores were added the significance level of this difference increased further (P<0.0001) as did the statistical power of the difference to 99.9%, thus increasing the robustness of the selection package.

CONCLUSION

The results from this study suggest that the assessment protocol we used to select individuals for HST in plastic surgery reliably and statistically significantly discriminated between the performances of candidates.

Toward using delta13C of ecosystem respiration to monitor canopy physiology in complex terrain

In 2005 and 2006, air samples were collected at the base of a Douglas-fir watershed to monitor seasonal changes in the delta13CO2 of ecosystem respiration (delta13C(ER)). The goals of this study were to determine whether variations in delta13C(ER) correlated with environmental variables and could be used to predict expected variations in canopy-average stomatal conductance (Gs). Changes in delta13C(ER) correlated weakly with changes in vapor pressure deficit (VPD) measured 0 and 3-7 days earlier and significantly with soil matric potential (psi(m)) (P value <0.02) measured on the same day. Midday G (s) was estimated using sapflow measurements (heat-dissipation method) at four plots located at different elevations within the watershed. Values of midday Gs from 0 and 3-7 days earlier were correlated with delta13C(ER), with the 5-day lag being significant (P value <0.05). To examine direct relationships between delta13C(ER) and recent Gs, we used models relating isotope discrimination to stomatal conductance and photosynthetic capacity at the leaf level to estimate values of stomatal conductance ("Gs-I") that would be expected if respired CO2 were derived entirely from recent photosynthate. We compared these values with estimates of Gs using direct measurement of transpiration at multiple locations in the watershed. Considering that the approach based on isotopes considers only the effect of photosynthetic discrimination on delta13C(ER), the magnitude and range in the two values were surprisingly similar. We conclude that: (1) delta13C(ER) is sensitive to variations in weather, and (2) delta13C(ER) potentially could be used to directly monitor average, basin-wide variations in Gs in complex terrain if further research improves understanding of how delta13C(ER) is influenced by post-assimilation fractionation processes.

Terminal myelocystocele and sacrococcygeal teratoma: a comparison of fetal ultrasound presentation and perinatal risk

This case exemplifies the difficulty in differentiating cystic sacrococcygeal teratoma and terminal myelocystocele. Fetal sonography presentation and perinatal risks of sacrococcygeal teratoma and terminal myelocystocele are compared, and we emphasize the importance of obtaining fetal MR imaging to establish an accurate diagnosis.

Backyard burning

This study was undertaken to determine whether changes had occurred in the numbers of burns that could be related to backyard burning subsequent to the introduction of the council tax throughout Eire for the collection of household refuse. Numbers of patients admitted to our unit who had sustained burns by burning rubbish were recorded prospectively over a period of 12 months. A random control group was taken as three years prior to this and results found by retrospective chart review. Between January and November 2005, 168 patients were admitted to the National Burns Unit, St James's Hospital Dublin, Ireland. Nineteen of these patients sustained flame burns from backyard burning. One hundred and seventy patients were admitted in the comparative period of 2002; Seven of these from backyard burning. The total number of inpatient days for these patients in 2005 (255) was significantly more than in 2002 (68) (p=0.024). The numbers in our study show a marked increase in the number of patients sustaining burns in this manner, and appear to correlate with the introduction of bin charges by a number of county councils around the country last year. This study demonstrates that the introduction of legislation can have an unforeseen adverse affect on the population if not introduced in correlation with appropriate public education. While the introduction of waste charges represents a very necessary move forward in waste disposal in Ireland, public awareness campaigns should be implemented to prevent further such injuries from occurring.

Parafibromin is a nuclear protein with a functional monopartite nuclear localization signal

Parafibromin is a nuclear protein with a tumour suppressor role in the development of non-hereditary and hereditary parathyroid carcinomas, and the hyperparathyroidism-jaw tumour (HPT-JT) syndrome, which is associated with renal and uterine tumours. Nuclear localization signal(s), (NLS(s)), of the 61 kDa parafibromin remain to be defined. Utilization of computer-prediction programmes, identified five NLSs (three bipartite (BP) and two monopartite (MP)). To investigate their functionality, wild-type (WT) and mutant parafibromin constructs tagged with enhanced green fluorescent protein or cMyc were transiently expressed in COS-7 cells, or human embryonic kidney 293 (HEK293) cells, and their subcellular locations determined by confocal fluorescence microscopy. Western blot analyses of nuclear and cytoplasmic fractions from the transfected cells were also performed. WT parafibromin localized to the nucleus and deletions or mutations of the three predicted BP and one of the predicted MP NLSs did not affect this localization. In contrast, deletions or mutations of a MP NLS, at residues 136-139, resulted in loss of nuclear localization. Furthermore, the critical basic residues, KKXR, of this MP NLS were found to be evolutionarily conserved, and over 60% of all parafibromin mutations lead to a loss of this NLS. Thus, an important functional domain of parafibromin, consisting of an evolutionarily conserved MP NLS, has been identified.

White particulate matter found in blood collection bags consist of platelets and leukocytes

BACKGROUND

In late January 2003, some blood centers and hospitals throughout the US voluntarily sus-pended the use of some RBC and plasma units for trans-fusion due to the presence of unknown white particulate matter (WPM) in these units. To better understand the WPM phenomena, a number of technologies were used to establish the nature of the particulates observed in Terumo Collection sets.

STUDY DESIGN AND METHODS

All AS-5 nonleuko-reduced RBCs and plasma units were visually inspected for WPM by placing the bags on a flat counter, undisturbed, for approximately 10 minutes and then perform-ing a visual examination for particles. Particles were isolated and placed on microscope slides or in plastic tubes for further analysis. Electron microscopy, bright field microscopy, differential interference contrast microscopy, infrared spectroscopy, and flow cytometry procedures were performed to establish the nature of the particulate matter. In addition, leukoreduction filters and blood transfusion sets were used on RBCs units with WPM.

RESULTS

The particles were mostly composed of PLTs and WBCs, and fragments of these cells. All macroscopic WPM was removed from RBCs with leukoeduction and transfusion filters.

CONCLUSIONS

WPM originated from PLTs and WBCs. Foreign matter (e.g., plastic) was not observed in any of the units. Leukoreduction and transfusion filters can be used to remove macroscopic WPM.

Multiple endocrine neoplasia type 1 (MEN1) germline mutations in familial isolated primary hyperparathyroidism

BACKGROUND

Familial isolated hyperparathyroidism (FIHP) is an autosomal dominant disorder characterized by uniglandular or multiglandular parathyroid tumours that occur in the absence of other endocrine tumours. The disorder may represent either an early stage of multiple endocrine neoplasia type 1 (MEN1), or an allelic variant of MEN1, or a distinct entity involving another locus. We have explored these possibilities in seven families in whom primary hyperparathyroidism occurred as the sole endocrinopathy.

METHODS

Seven FIHP families were ascertained and venous blood samples obtained from 35 members (17 affected and 18 unaffected) for DNA sequence analysis of the MEN1 gene. The mean (+/- SD) follow-up period in the 17 affected members was 15.06 (+/- 8.83) years.

RESULTS

Four heterozygous germline mutations of the MEN1 gene were identified. These consisted of two 4-bp intragenic deletions that would result in prematurely truncated proteins, and two missense (Asp153Val and Ala411Pro) mutations. Furthermore, analysis of parathyroid tumour DNA from one individual revealed a loss of the wild-type allele and retention of the mutant allele, consistent with Knudson's 'two-hit' model of hereditary cancer and a tumour suppressor role for MEN1 in FIHP.

CONCLUSIONS

Our results provide further support for FIHP being a distinct allelic variant of MEN1, and an analysis of the 16 mutations reported to date indicate that FIHP is associated with a higher frequency of missense MEN1 mutations.

HRPT2, encoding parafibromin, is mutated in hyperparathyroidism-jaw tumor syndrome

We report here the identification of a gene associated with the hyperparathyroidism-jaw tumor (HPT-JT) syndrome. A single locus associated with HPT-JT (HRPT2) was previously mapped to chromosomal region 1q25-q32. We refined this region to a critical interval of 12 cM by genotyping in 26 affected kindreds. Using a positional candidate approach, we identified thirteen different heterozygous, germline, inactivating mutations in a single gene in fourteen families with HPT-JT. The proposed role of HRPT2 as a tumor suppressor was supported by mutation screening in 48 parathyroid adenomas with cystic features, which identified three somatic inactivating mutations, all located in exon 1. None of these mutations were detected in normal controls, and all were predicted to cause deficient or impaired protein function. HRPT2 is a ubiquitously expressed, evolutionarily conserved gene encoding a predicted protein of 531 amino acids, for which we propose the name parafibromin. Our findings suggest that HRPT2 is a tumor-suppressor gene, the inactivation of which is directly involved in predisposition to HPT-JT and in development of some sporadic parathyroid tumors.

2-methoxyestradiol induces interferon gene expression and apoptosis in osteosarcoma cells

2-Methoxyestradiol (2-ME), a naturally occurring mammalian metabolite of 17beta-estradiol, has been implicated as a physiological inhibitor of tumor cell proliferation. In this study, the effects of 2-ME on cultured osteosarcomatous cells were investigated. Dose-dependent growth inhibition was observed in MG63 and TE85 human osteosarcoma cells exposed to 2-ME. The cell killing by 2-ME was ligand-specific; the immediate precursor (2-hydroxyestradiol), the parent compound (17beta-estradiol), and the equivalent metabolite of estrone (2-methoxyestrone) exhibited less potency and efficacy. Furthermore, 2-ME was similarly effective at killing immortalized human fetal osteoblastic cells (hFOB) with and without estrogen receptor-alpha and -beta and rat osteosarcoma cells (ROS17/2.8). The cytotoxicity of 2-ME was selective to transformed and immortalized osteoblastic cells; 2-ME (2 microm) had no effect on the proliferation of primary cultures of human osteoblasts. Co-treatment with the potent estrogen receptor ligand, ICI-182,780, did not reduce 2-ME-induced osteosarcoma cell death, implying that this action is not mediated by conventional estrogen receptors. The expression levels of bone matrix protein genes, type 1 collagen and osteonectin, were transiently reduced after 2-ME treatment, suggesting that the surviving cells are capable of producing bone matrix. The 2-ME-mediated killing of osteosarcoma cells was due to the induction of apoptosis; treatment induced expression of interferon genes within 12 h and histological evidence of apoptosis within 48 h of 2-ME treatment. Thus, our results demonstrate that 2-ME is highly cytotoxic to osteosarcoma cells but not normal osteoblasts. These findings suggest that further study of 2-ME as a potential intervention for treatment of osteosarcoma is warranted.

In-vivo measurement of activated microglia in dementia

BACKGROUND

Activated microglia have a key role in the brain's immune response to neuronal degeneration. The transition of microglia from the normal resting state to the activated state is associated with an increased expression of receptors known as peripheral benzodiazepine binding sites, which are abundant on cells of mononuclear phagocyte lineage. We used brain imaging to study expression of these sites in healthy individuals and patients with Alzheimer's disease.

METHODS

We studied 15 normal individuals (age 32-80 years), eight patients with Alzheimer's disease, and one patient with minimal cognitive impairment. Quantitative in-vivo measurements of glial activation were obtained with positron emission tomography (PET) and carbon-11-labelled (R)-PK11195, a specific ligand for the peripheral benzodiazepine binding site.

FINDINGS

In normal individuals, regional [11C](R)-PK11195 binding did not significantly change with age, except in the thalamus, where an age-dependent increase was found. By contrast, patients with Alzheimer's disease showed significantly increased regional [11C](R)-PK11195 binding in the entorhinal, temporoparietal, and cingulate cortex.

INTERPRETATION

In-vivo detection of increased [11C](R)-PK11195 binding in Alzheimer-type dementia, including mild and early forms, suggests that microglial activation is an early event in the pathogenesis of the disease.

Neuropsychological profiles of familial Alzheimer's disease associated with mutations in the presenilin 1 and amyloid precursor protein genes

Patients with familial Alzheimer's disease and a subset known to have presenilin mutations were compared with sporadic cases on a comprehensive battery of cognitive tests. These included measures of memory, intelligence, language and perception. The three groups were very comparable, in terms of severity, on global measures of dementia. However, their profiles/patterns of cognitive impairment differed in two respects; the group with sporadic Alzheimer's disease were significantly more impaired on tests of object naming and object perception than either the group with familial Alzheimer's disease or group with familial Alzheimer's disease and presenilin mutations, yet they scored at a significantly higher level on the measure of verbal intelligence. This study provides further evidence of the heterogeneity of the disease process.

MRI of the female pelvis

MRI is a proven modality to evaluate the female pelvis. Excellent soft tissue contrast, sensitivity for the detection of fluid, and the multiplanar imaging capabilities of MR allow noninvasive demonstration of normal anatomy and pathological processes. Most female pelvic MRI studies are performed to answer specific questions and must, therefore, follow carefully developed protocols, which are discussed in this article. The principal MRI techniques and strategies outlined in this work include: (1) the evaluation of reproductive dysfunction, anatomic variants; (2) specific obstetrical applications; (3) oncologic evaluation and tumor staging; (4) problem solving (i.e., the characterization of abnormalities detected by ultrasound); and (5) the evaluation of urethral disease.

Median nerve injury: an underrecognised complication of brachial artery cardiac catheterisation?

OBJECTIVE

To describe the local neurological complications associated with cardiac catheterisation via the right brachial artery.

METHODS

A follow up study to determine the mechanism of injury and outcome of patients who sustained a high median nerve palsy after this procedure. Five right handed patients were identified in a 24 month period. Each was assessed clinically and electrophysiologically at presentation. All were followed up initially (range six to 22 months) clinically, electrophysiologically, and using components from the Chessington occupational therapy neurological assessment battery (COTNAB) functional hand assessment.

RESULTS

The incidence of this complication was between 0.2 and 1.4%. Three mechanisms of injury were identified. These included direct nerve compression due to formation of antecubital fossa haematoma, direct nerve trauma, and ischaemia secondary to brachial artery occlusion. The initial neurological and nerve conduction deficits improved with time. However, all cases had persistent disability in hand function as documented clinically and on the dexterity and stereognosis subcomponent of the COTNAB test.

CONCLUSION

This is an uncommon, but probably underrecognised complication. Those performing cardiac catheterisation via the right brachial artery should be aware of the potential risks of damage to the median nerve. They should evaluate hand function after the procedure and take prompt action if median nerve dysfunction is noted. Damage to the median nerve results in appreciable long term disability, which may have medicolegal relevance.

Pressure ulcer prevention: review of literature

Much has been written about the causes, prevention, and nursing management of pressure ulcers. A review of current literature on the subject reveals that, in spite of the enormity of information available, the problem continues to consume a large percentage of nursing time and energy. Studies of aggressive prevention and ongoing continuing education programs have demonstrated significant reduction of incidence and time of treatment, as well as dramatic cost savings. The Agency for Health Care Policy and Research (AHCPR) has recommended that all patients at risk for pressure ulcer development be placed on some form of pressure-reducing support surface. There is a wide variety of these products available, but a surprisingly limited quantity of published articles specifically compare the efficacy of one product to another.

Fertilization-promoting peptide in reproductive tissues and semen of the male marmoset (Callithrix jacchus)

Fertilization-promoting peptide (FPP) is present in the prostate gland and semen of some mammals, and has been shown to enhance the fertilizing ability of both epididymal mouse and ejaculated human spermatozoa. The novel peptide may prove of importance for the treatment of some cases of male infertility, and a suitable animal model would be useful to test this hypothesis. To this end, we examined reproductive tissues and semen of the male marmoset for the presence of FPP. Peptides were extracted from seminal plasma, testes, prostate, and bulbourethral glands of intact and castrated male marmosets. The peptides were identified by ion-exchange chromatography followed by radioimmunoassay. The mean concentration of FPP immunoreactivity in semen from intact males was 58.7 nM (SE +/- 9.9 nM, n = 10), and anion-exchange chromatography revealed FPP as the only immunoreactive peptide present. Analysis of tissues revealed that FPP in semen was likely to be derived from the prostate gland, which contained this peptide as the major source of immunoreactivity (10.86 pmol/gland; SE +/- 4.39 pmol/gland, n = 4). Only low concentrations of FPP were detectable in the bulbourethral glands, and the peptide was undetectable in the testis. Surprisingly, FPP was readily detectable in the seminal plasma from one castrated marmoset and was present in the prostate gland from 3 castrates at levels which did not differ significantly from those in intact animals (5.47 pmol/gland, SE +/- 1.64 pmol/gland, n = 3). Plasma testosterone measurements indicated that residual circulatory androgens remained after castration, which may be consistent both with the maintenance of mating behavior and the presence of prostatic FPP. We conclude that FPP is present within the prostate gland and seminal plasma of the marmoset at concentrations consistent with a role in male fertility in this species.

Clinicopathological features of familial Alzheimer's disease associated with the M139V mutation in the presenilin 1 gene. Pedigree but not mutation specific age at onset provides evidence for a further genetic factor

Sixteen affected individuals are described from two families with early onset autosomal dominant familial Alzheimer's disease. A mutation at codon 139 in the presenilin 1 gene on chromosome 14 results in a methionine to valine substitution which cosegregates with the disease in these families. Onset of dementia was before the age of 50 years in all individuals. The ages at onset within each family were tightly clustered but were significantly different between the families; this difference could not be accounted for by apolipoprotein E status and suggests the existence of a further genetic factor that modifies age at disease onset. The pattern of cognitive decline was similar in both families: early memory loss (initially selective for verbal memory in some individuals) was followed soon after by loss of arithmetic skills while naming and object perception skills were relatively preserved. A speech production deficit was observed in three members of one family but not in the other. Seizures were common and usually predated by myoclonic jerks by a number of years. Serial MRIs showed progressive cortical atrophy with periventricular white matter change appearing 3-4 years into the disease. PET revealed parieto-temporal hypometabolism in all individuals scanned. The diagnosis of Alzheimer's disease was confirmed with typical histopathology in one individual from each family.

Presymptomatic hippocampal atrophy in Alzheimer's disease. A longitudinal MRI study

The hippocampal formation (HF) is known from pathological and MRI studies to be severely atrophied in established Alzheimer's disease. However, it is unclear when the earliest changes in the HF occur. We performed a longitudinal study of asymptomatic individuals at risk of autosomal dominant familial Alzheimer's disease in order to assess presymptomatic changes in the HF. Seven at risk members of a familial Alzheimer's disease pedigree associated with the amyloid precursor protein 717 valine to glycine mutation underwent serial MR scanning and neuropsychological assessments over 3 years. These assessments were compared with results from 38 normal controls. During the study three at risk subjects became clinically affected. Volumetric measurement of the HF showed that asymmetrical atrophy developed in these subjects before the appearance of symptoms. Verbal and visual memory measures declined in parallel with hippocampal loss. A loss of up to 8% per annum of the volume of the HF occurred in the 2 years over which symptoms first appeared. These findings may have implications for early diagnosis of Alzheimer's disease.

Clinical and neuroimaging features of familial Alzheimer's disease

Subtle phenotypic differences between familial Alzheimer's disease (FAD) pedigrees can be identified which may reflect the genetic and allelic heterogeneity of the disease. Positron emission tomography (PET) of APP mutation and chromosome 14-linked FAD pedigree members reveals biparietal bitemporal hypometabolism. Scanning of asymptomatic at-risk individuals reveals a similar, but quantitatively less severe, pattern of hypometabolism.

The use of xenon-133 for measurement of blood flow through systemic arteriovenous malformations before and after therapeutic embolization

Embolization is increasingly used to treat systemic arteriovenous (AV) shunts although its success, as judged by either angiographic or clinical means, is difficult to quantify. The aim of the study was to quantify blood flow through AV shunts with 133Xe, which, because of its relatively long transit time through peripheral tissues, behaves like microspheres. Following arterial injection, 133Xe entering an AV shunt rapidly arrives in the lung and can be quantified with a scintillation probe. In 17 patients with systemic AV shunts, the reduction in shunt flow following therapeutic embolization was quantified in the angiography theatre by comparing the initial count rates in the lung, recorded by probe, following injection of identical quantities of 133Xe into a supplying artery before and after embolization. By comparing the lung counts with those given by an intravenous injection of 133Xe, the fraction of flow at the catheter tip entering the shunt was also quantified. Tissue perfusion in the vascular territory distal to the shunt was measured at the same time by recording the clearance of non-shunted 133Xe with a second probe over the extremity. Control injections of 133Xe were given in the contralateral limb in order to assess 133Xe transit in the absence of shunting and to compare tissue perfusion between the two sides. Shunt flow ranged from 40% to 100% (of that at the tip of the catheter) (n = 14), while the reduction in shunt flow following embolization ranged from 15% to 96% (n = 19). Tissue perfusion distal to the shunt and in the contralateral limb was about 5 ml 100 ml-1 min-1. Contrast medium had no consistent effect on tissue perfusion in either limb, or on shunt flow. There was no difference in peripheral perfusion between the abnormal and control sides, nor any significant difference in perfusion in the distal tissue on the abnormal side before and after embolization. There was, however, a consistent increase in the fraction of the injected 133Xe delivered to the distal tissue after embolization (median increase 93%, p < 0.001). The technique is relatively simple and merits further development as a means of continuous quantification of systemic AV shunt flow in the angiography theatre at the time of embolization.

Deficits in cerebral glucose metabolism demonstrated by positron emission tomography in individuals at risk of familial Alzheimer's disease

In order to establish whether positron emission tomography (PET) can identify metabolic changes in Alzheimer's disease at a presymptomatic stage, we have examined 24 asymptomatic at risk individuals from families with Alzheimer's disease. A significant reduction in global cerebral metabolic rate for glucose was found when compared with 16 age-matched controls. There was also a focal, parieto-temporal deficit similar to, although less extensive than, that found in 18 symptomatic individuals from familial Alzheimer's disease (FAD) pedigrees. Follow up of this cohort will establish whether these metabolic changes relate to a presymptomatic stage of the disease.

Chromosome 14 linked familial Alzheimer's disease. A clinico-pathological study of a single pedigree

The clinical features of three affected members of a British pedigree with familial Alzheimer's disease are presented. This pedigree is one of six included in an earlier study which demonstrated linkage to chromosome 14. The individuals were investigated clinically and neuropsychologically, using both PET and MRI over a 4-year period. Further information from three deceased individuals was obtained, including histopathological confirmation of Alzheimer's disease in one case which came to autopsy. The mean age at onset for this family was 43 years. Neurological examination revealed myoclonic jerks in all cases, and one patient was documented to have seizures. Strikingly similar neuropsychological profiles were observed, characterized by an initial memory deficit with early dyscalculia and an impairment in speech production with relative absence of anomia. All individuals showed mild degrees of cerebral atrophy and two individuals had periventricular white matter lesions. PET scanning using [18F]fluorodeoxyglucose showed parieto-temporal hypometabolism in all cases and the two severely affected patients with speech production changes had additional left-sided frontal hypometabolism involving Broca's area. The least affected case initially had a more asymmetrical reduction in metabolism in the left inferior temporal and supramarginal gyri; a follow-up scan showed that this deficit had become bilateral and more severe. These clinical and neuroimaging features have not been previously reported in chromosome 14 linked pedigrees; the phenotypic variability between families suggests allelic heterogeneity at the chromosome 14 locus.

Positron emission tomography in familial Alzheimer disease

There is increasing evidence for genetic heterogeneity in Alzheimer disease. A longitudinal clinical and imaging study had been established in order to determine whether specific phenotypic profiles are present in aetiologically distinct familial Alzheimer disease (FAD) pedigrees. [18F]fluorodeoxyglucose positron emission tomography has been used in conjunction with statistical parametric mapping to determine the relative distribution of hypometabolism. A parietotemporal deficit has been observed in individuals from both amyloid precursor protein mutation and chromosome 14 linked FAD families. Preliminary data from asymptomatic individuals at risk of FAD shows similar, although a less extensive pattern of deficit.

The earliest cognitive change in a person with familial Alzheimer's disease: presymptomatic neuropsychological features in a pedigree with familial Alzheimer's disease confirmed at necropsy

Comprehensive, longitudinal neuropsychological assessments are reported in a person "at risk" from autosomal dominant, necropsy confirmed familial Alzheimer's disease. The first assessment showed a moderately selective verbal memory deficit in the context of mild general intellectual impairment. Subsequent testing showed the progressive deterioration of visual memory and a mild decline of perceptual and spatial skills. Language and literacy skills, however, remained comparatively intact. The neuropsychological profiles obtained at each assessment are presented in profile maps. These permit direct longitudinal comparison of cognitive function, and may serve in the comparison of different potential cases of familial Alzheimer's disease. This case sought medical attention for memory difficulties 26 months after the first neuropsychological assessment. These results mark the first cognitive manifestations in a pedigree with familial Alzheimer's disease which, in this case, were seen presymptomatically. The findings are discussed in relation to neuropsychological studies of affected cases, and in terms of their reflecting the heterogeneous nature of familial Alzheimer's disease.

The genetics of Alzheimer's disease

The discovery of pathogenic mutations in the amyloid precursor protein gene in families with Alzheimer's disease is a major advance in the understanding of the pathogenesis of Alzheimer's disease. In certain families at least, beta-amyloid metabolism plays a central role in the disease process. It is tempting to speculate that beta-amyloid is common to the majority of Alzheimer cases. In the immediate future the discovery of the mutations responsible for the condition in those families that show linkage to chromosomes 14 and 19 will enable it to be established whether beta-amyloid is involved in these pedigrees as well. If amyloid metabolism is involved in APP and chromosomes 14 and 19 families, it suggests that Alzheimer's disease is a single disease with a common metabolic pathway. However, if other mechanisms are implicated, evidence is provided that Alzheimer's disease is a heterogeneous disorder that shares common clinicopathological features.

Alzheimer's disease families with amyloid precursor protein mutations

Early onset Familial Alzheimer's Disease (FAD) is an autosomal dominant disease with apparent complete penetrance. It is genetically heterogeneous with some families carrying mutations in the amyloid precursor protein (APP) gene which segregate with the disease. In addition, there is allelic heterogeneity with four mutations associated with FAD. Three mutations have been reported at APP 717, just distal to the C-terminus of the beta-amyloid domain, APP 717 val-ile, APP 717 val-phe, and APP 717 val-gly, which are associated with autopsy-proven Alzheimer's disease (AD). APP 670/671 lies at the N terminus of the beta-amyloid domain and is associated with clinically diagnosed FAD in two Swedish families. FAD tends to have prominent myoclonus and this is shared by the cases with APP mutations. In two unrelated UK families with APP 717 val-ile mutations there was early prominent memory impairment with dyscalculia proceeding to generalized cognitive impairment with a lack of insight. There was a late development of a gait disturbance with extrapyramidal features in some members. Positron emission tomography (PET) with fluorodeoxyglucose demonstrated posterior bitemporal biparietal hypometabolism in one case. Magnetic resonance imaging (MRI) showed generalized cerebral atrophy particularly affecting the temporal lobes and hippocampus. At autopsy, a single case showed extensive beta-amyloid deposition with congophilic angiopathy and widespread senile plaques and neurofibrillary tangles. The cytoskeletal pathology associated with abnormally phosphorylated tau was similar to cases of sporadic AD. In addition, there were widespread cortical and subcortical Lewy bodies. A single family with the APP 717 val-gly mutation also showed prominent myoclonus, lack of insight, and seizures, PET, in a single case, showed classical biparietal bitemporal hypometabolism. Autopsy, in a single case, showed diffuse deposits of beta-amyloid throughout the cortex with frequent neuritic plaques and neurofibrillary tangles. No other inclusion bodies were seen. There was severe congophilic angiopathy. The age at onset of APP mutations is around 50 years of age by contrast to other early onset FAD pedigrees.

Familial Alzheimer's disease. A pedigree with a mis-sense mutation in the amyloid precursor protein gene (amyloid precursor protein 717 valine-->glycine)

Ten affected individuals are described from a kindred with autosomal dominant familial Alzheimer's disease in which a mutation in the amyloid precursor protein gene results in a valine to glycine substitution at amyloid precursor protein 717 which co-segregates with the disease. The mean age at onset of symptoms was 52 years with a range from 40 years to 67 years. The median duration of the disease was 11 years, with a range of 7-16 years. All individuals fulfilled the National Institute for Neurological and Communicative Disorders and Stroke criteria for probable Alzheimer's disease. A homogeneous clinical and neuropsychological pattern was evident within the family. Myoclonic jerks, seizures, depression and a lack of insight were common features. Positron emission tomography demonstrated biparietal bitemporal hypometabolism in the one affected individual who was studied. The diagnosis was confirmed histopathologically in one individual.