A multi-disciplinary commentary on preclinical research to investigate vascular contributions to dementia

Although dementia research has been dominated by Alzheimer's disease (AD), most dementia in older people is now recognised to be due to mixed pathologies, usually combining vascular and AD brain pathology. Vascular cognitive impairment (VCI), which encompasses vascular dementia (VaD) is the second most common type of dementia. Models of VCI have been delayed by limited understanding of the underlying aetiology and pathogenesis. This review by a multidisciplinary, diverse (in terms of sex, geography and career stage), cross-institute team provides a perspective on limitations to current VCI models and recommendations for improving translation and reproducibility. We discuss reproducibility, clinical features of VCI and corresponding assessments in models, human pathology, bioinformatics approaches, and data sharing. We offer recommendations for future research, particularly focusing on small vessel disease as a main underpinning disorder.

Postmastectomy Radiation Therapy Planning After Immediate Implant-based Reconstruction Using the European Society for Radiotherapy and Oncology-Advisory Committee in Radiation Oncology Practice Consensus Guidelines for Target Volume Delineation

AIMS

To evaluate how common radiation therapy techniques perform in the setting of the new European Society for Radiotherapy and Oncology-Advisory Committee in Radiation Oncology Practice (ESTRO-ACROP) delineation recommendations for immediate breast reconstruction (IBR).

MATERIALS AND METHODS

Seven Danish radiation therapy centres and six international European centres participated in this project. Two breast cancer cases (one left-sided and one right-sided) with a retropectoral implant were chosen for radiation therapy planning using deep-inspiration breath-hold. Target volumes were delineated according to ESTRO-ACROP delineation recommendations. The centres were asked to plan the cases using any radiation therapy technique according to the Danish Breast Cancer Group plan objectives.

RESULTS

In total, 35 treatment plans were collected. Half of the submitted plans, for both the left-sided and the right-sided case, used the field-in-field (FiF) technique (nine for each), a quarter used volumetric arc radiation therapy (VMAT; five for right-sided, four for left-sided) and the remaining quarter was a mix of inverse intensity-modulated radiation therapy (IMRT), helicoidal therapy and hybrid (combined open fields and VMAT) techniques. Mean clinical target volume doses were in the range 99-102% of the prescribed dose. The median FiF mean heart dose (MHD) for right-sided radiation therapy was 1 Gy (range 0.8-3.7) and 5.2 Gy for left-sided radiation therapy (range 2.2-6.5). For right-sided radiation therapy, the median VMAT MHD was 3.42 Gy, for IMRT was 2.3 Gy and for helicoidal therapy was 5.1 Gy. For left-sided radiation therapy, the median VMAT MHD was 6.3 Gy, for IMRT was 7.8 Gy and for helicoidal therapy was 7.3 Gy.

CONCLUSIONS

Different radiation therapy techniques could be used to plan radiation therapy in the setting of IBR. FiF provided good coverage with acceptable organ at risk doses. The best dose distribution results as a trade-off between the objectives of target volume coverage and high-dose organ at risk inclusion. The radiation therapy technique affects the interplay between these objectives.

Assessing the role of the growth hormone secretagogue receptor in motivational learning and food intake

The orexigenic neuropeptide ghrelin is an endogeneous ligand for the growth hormone secretagogue receptor (GHS-R). This orexigen is expressed in both the periphery and in the central system, including portions of mesolimbic dopaminergic circuitry that play a role in affective behaviors. Here we examined pharmacological antagonism of GHS-R in motivational incentive learning, as reflected in Pavlovian-to-instrumental transfer (PIT). Furthermore, it is currently unclear whether the previous effects of ghrelin on food intake are mediated by pre- and/or postingestive influences on ingestive behavior. Thus, the authors also conducted detailed analyses of the temporal dynamics of sucrose licking. Mice received low (50 nmol), moderate (100 nmol), and high (200 nmol) intraperitoneal injections of the GHS-R antagonist GHRP-6 [D-Lys3] prior to subsequent transfer and sucrose consumption tests. Low and moderate doses led to an augmentation of PIT, while high dose injections led to generalized performance deficits. In addition, moderate and high doses of the antagonist resulted in reductions in sucrose intake by reducing palatability of the sucrose. These results suggest dissociable functions of GHS-R in its influence over motivational learning and ingestive behavior.

Changing presentation and management of neutropenic enterocolitis

OBJECTIVE

To characterize the current clinical presentation and management of neutropenic enterocolitis.

DESIGN

Retrospective review of records of oncology unit patients requiring general surgical consultation for abdominal complaints in a 1-year period.

SETTING

Oncology unit of a tertiary care, university teaching hospital.

PATIENTS AND INTERVENTIONS

Fourteen patients diagnosed as having neutropenic enterocolitis were managed conservatively with operation reserved for failure of conservative therapy.

MAIN OUTCOME MEASURES

Clinical data from patients at the time of presentation and during treatment for neutropenic enterocolitis.

RESULTS

All 14 patients diagnosed as having neutropenic enterocolitis were receiving chemotherapy for solid tumors or leukemias. Seven patients were undergoing stem cell or autologous bone marrow transplantation. Presenting symptoms and physical examination findings were nonspecific. All patients except one had neutropenia at the time of diagnosis. Computed tomographic scans of the abdomen were the most useful confirmatory study for the diagnosis of neutropenic enterocolitis. All patients except one had resolution of neutropenic enterocolitis with conservative therapy. One patient whose course of conservative management failed had protracted neutropenia and required operation for resection of bowel with full-thickness necrosis.

CONCLUSIONS

Neutropenic enterocolitis has evolved from a complication of patients with leukemia to a disease of patients receiving high-dose chemotherapy for many malignancies, solid as well as hematologic. Diagnosis of neutropenic enterocolitis continues to be a challenge, as patients typically present with nonspecific gastrointestinal tract symptoms. Neutropenia and computed tomographic scan findings are useful adjuncts in diagnosing neutropenic enterocolitis. Timely conservative treatment frequently allows resolution of neutropenic enterocolitis without operation.

Analysis of pulse oximetry data in normal sleeping children

This study was designed to determine the range of oxygen saturation levels encountered in normal sleeping children up to 10 years of age in their own home environment. Subjects were chosen by stratified random sampling from the general practice list of the town of Frome, Somerset, UK. Analysis of overnight pulse oximetry recordings allowed a normal range for the following parameters of oxygen saturation level to be reported: mean, median, mode, maximum, fifth centile, upper and lower quartiles and the number of greater than 4% dips in oxygen saturation per hour. As a consequence of this study the values given can now be used to identify those children with abnormal sleep patterns.

The reproducibility of urinary growth hormone measurement in children undergoing adenotonsillectomy: a pilot study

The reproducibility of urinary growth hormone levels in normal children and in children undergoing adenotonsillar surgery was investigated. Thirty normal children and 32 children pre- and post-adenotonsillectomy had overnight urinary growth hormone levels measured on two consecutive nights using the technique of immunoradiometric assay. There was no significant difference when levels in each of these groups were compared. Therefore, the results were pooled (n = 94) and the correlation coefficient comparing levels obtained on the first and the second consecutive nights sample was calculated, r = 0.644 (P < 0.001). This work suggests that studies of urinary growth hormone levels in children give reproducible results. Further investigation of this technique as a screening or diagnostic procedure in the clinical setting can now be more widely evaluated.

Differential regulation of APP secretion by apolipoprotein E3 and E4

The apolipoprotein E isozyme, apolipoprotein E4, has been implicated as a risk factor for Alzheimer's disease. One reason for the increased risk may be that apolipoprotein E binds to the A beta peptide, but there may be other factors as well. We show that apolipoprotein E is a potent regulator of the secretion of amyloid precursor protein. In cultures of PC12 cells, nanomolar levels of apolipoprotein E3 induce a rapid decrease in the secretion of APP, being observable in 30 min. and stable over 24 hours. Apolipoprotein E4, in contrast, increases secretion of APP over a similar time course. Reciprocal changes occur in cellular amyloid precursor protein. Differential characteristics are also seen in apo E binding to the cells, where apo E4 binds over a slower time course than apo E3. These results suggest a novel mechanism by which apolipoprotein E may be influencing the metabolism of amyloid precursor protein.

Screening for obstructive sleep apnoea in children

The prevalence of OSA increases with age depending on the techniques used and criteria accepted for definition of the condition. In children there may be a relationship of snoring to parental smoking. Night time problems may be worsened by use of anti-histamine sympathomimetic amine medication or cough suppressants. Disorders of sleep affect not only the child but also the parents and family. Progression to right heart failure is very rare and more likely in syndromic conditions. Whilst polysomnography will detect most of the changes of OSA, pulse oximetry may detect only two-thirds of adults with the condition and until now there has been no data for normal children examined at home.

Tinnitus in pregnancy

The presence of tinnitus in pregnancy was investigated by a postal questionnaire survey. A group of pregnant women attending the ante-natal clinic and a control group of non-pregnant members of the nursing staff at the Royal United Hospital in Bath were studied. The prevalence of tinnitus in the pregnant and non-pregnant women was compared. Both groups were similar in age, previous noise exposure and the presence of ear disease or operations. Twenty-five per cent of the pregnant women reported tinnitus compared with 11% of the control group. Chi-square analysis of this data gives a value of chi 2 = 4.07, d.f. = 1, P < 0.05. The result of our survey shows that there is significantly increased prevalence of tinnitus in pregnant women compared with a similar non-pregnant control group. This association has not been previously reported.

Adenoid cystic carcinoma: the results of radical surgery

A personal series of 267 salivary tumours seen in a 20-year period was reviewed. Thirty-six patients with a previously untreated histologically proven adenoid cystic carcinoma of the major and minor salivary glands were submitted to radical surgery. The 5-year survival was 73%; no patient died of disease or suffered a recurrence of disease beyond the 5-year mark, suggesting that radical surgery achieves good results and largely pre-empts the notorious pattern of repeated recurrence. Only 8% of the patients died solely of primary recurrence, suggesting that the place of supraradical surgery is likely to be very limited.