Cortical thickness and hippocampal shape in pure vascular mild cognitive impairment and dementia of subcortical type

BACKGROUND AND PURPOSE

The progression pattern of brain structural changes in patients with isolated cerebrovascular disease (CVD) remains unclear. To investigate the role of isolated CVD in cognitive impairment patients, patterns of cortical thinning and hippocampal atrophy in pure subcortical vascular mild cognitive impairment (svMCI) and pure subcortical vascular dementia (SVaD) patients were characterized.

METHODS

Forty-five patients with svMCI and 46 patients with SVaD who were negative on Pittsburgh compound B (PiB) positron emission tomography imaging and 75 individuals with normal cognition (NC) were recruited.

RESULTS

Compared with NC, patients with PiB(-) svMCI exhibited frontal, language and retrieval type memory dysfunctions, which in patients with PiB(-) SVaD were further impaired and accompanied by visuospatial and recognition memory dysfunctions. Compared with NC, patients with PiB(-) svMCI exhibited cortical thinning in the frontal, perisylvian, basal temporal and posterior cingulate regions. This atrophy was more prominent and extended further toward the lateral parietal and medial temporal regions in patients with PiB(-) SVaD. Compared with NC subjects, patients with PiB(-) svMCI exhibited hippocampal shape deformities in the lateral body, whilst patients with PiB(-) SVaD exhibited additional deformities within the lateral head and inferior body.

CONCLUSIONS

Our findings suggest that patients with CVD in the absence of Alzheimer's disease pathology can be demented, showing cognitive impairment in multiple domains, which is consistent with the topography of cortical thinning and hippocampal shape deformity.

The optimization of ELISA for methamphetamine determination: the effect of immunogen, tracer and antibody purification method on the sensitivity

To obtain more sensitive immunoassay for methamphetamine (MA) determination, the optimum condition of enzyme-linked immunosorbent assay (ELISA) was investigated in regard to immunogens, antibody purification methods and coating tracers. Activated MA, N-(4-aminobutyl)methamphetamine (4-ABMA), was conjugated with bovine serum albumin (BSA) or keyhole limpet hemocyanin (KLH) and used as immunogen. The antibodies were purified by protein G chromatography or various immunoaffinity chromatography-linked MA-protein ligands, such as MA-BSA, MA-KLH or MA-ovalbumin (OVA). Each purified antibody was characterized by means of sensitivity and cross-reactivity using the three MA-protein coating tracers, MA-BSA, MA-KLH and MA-OVA. The best sensitivity of each antibody was acquired with the MA-OVA tracer although the tracer concentration and the antibody titer level at optimum condition were varied. The antibody with high titer level did not always yield good sensitivity. At optimum condition, immunoaffinity chromatography-purified antibodies were better for sensitivity and for specificity than protein G-purified antibodies. The cross-reactivity of the purified antibodies seemed to be affected by immunogen structure and showed somewhat different patterns according to the immunoaffinity ligand utilized. These data show that the antibody purification method as well as choice of coating tracer and immunogen is essential for the sensitivity and specificity of EIA; the optimum condition for assay should be discovered using various methods and combinations.

A case of myelopathy, myopathy, peripheral neuropathy and subcortical grey matter degeneration associated with recessive compound heterozygous POLG1 mutations

This 54year old woman presented with symptoms of sensory ataxic neuropathy, with cerebellar features. She developed further weakness, visual disturbances with diplopia, dysarthria and dysphasia. After her death at 66years, she was found to have compound heterozygous mutations of POLG1 gene in muscle, and Southern blot showed low levels of multiple deletions of mitochondrial DNA. Neuropathological examination showed profound dorsal column and dorsal spinocerebellar tract degeneration, degeneration of dorsal root ganglia and Clarke's nucleus in spinal cord and severe predominantly sensory peripheral neuropathy. The brain showed severe neuronal loss and gliosis in substantia nigra, medial posterior thalamus and head of caudate. Excess numbers of COX-negative fibres and "ragged-red" fibres were found in five skeletal muscles sampled.

Long-term results of salvage cryotherapy for prostate cancer

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Background: The optimum treatment of Prostate cancer recurrence following external bean radiation therapy (EBRT) remains a controversial topic. The primary problem with comparing salvage techniques following EBRT is the lack of long term data. We reviewed the long- term overall survival, disease-specific survival and disease free survival of patients who have undergone salvage cryotherapy to the prostate gland.

Methods: A retrospective analysis was performed on all patients undergoing salvage cryotherapy for locally recurrent prostate cancer after EBRT by a single surgeon at a single institution from 1995-2004. Patients preoperative, perioperative and postoperative data was reviewed and recorded. Should a patient no longer be followed by the urology service the Patients and the patient's primary care physician or urologist were contacted. Mortality data, PSA results, bone scan results and any details of hormone therapy were recorded for this study.

Results: 187 patients were included in the current study from which 176 patients had records available for follow up giving a follow up rate of 94%. Mean follow up was 7.46 years (1-14 years). 52 patients were followed for greater than 10 years. Average time to prostate cancer recurrence in patients who developed recurred was 2.3 years and average time to hormone therapy in these patients was 2.8 years. Overall survival at 10 years was high at 87%. Risk factors for recurrence of tumour identified were presalvage PSA, preradiation and presalvage gleason score. Preradiation gleason score had little impact on survival. PSA nadir of >1.0ng/mL was highly predictive of early recurrence. Disease-free survival rates of between 39 and 64% depending on risk factors.

Conclusions: Cryotherapy has a definite role in the management of prostate cancer, representing a minimally invasive salvage treatment with acceptable 10 year disease free survival (DFS) of upwards of 39% and specific groups attaining 10 year DFS of 64%. Presalvage PSA and Gleason score are the best predictors of disease recurrence, whilst preradiation gleason score did not correlate with risk of disease recurrence. A PSA Nadir greater than 1 ng/mL indicates a poor prognosis in which early ADT should be strongly considered.

No significant financial relationships to disclose.

Long-term outcome of randomized trial between cryoablation and external beam therapy for locally advanced prostate cancer (T2C-T3B)

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Background: Our primary objective is to assess and compare the survival outcomes between cryoablation (CRYO) and external beam radiation therapy (EBRT) in locally advanced prostate cancer.

Methods: This is a single institution, retrospective study. Our institution ethics board had approved this study. Patients were initially recruited for the trial between 1999 and 2002. The inclusion criteria for the trial were patients with cT2c–cT3b prostate cancer, PSA < 25ng/ml, with negative metastatic evaluation on CT and bone scan. Patients with evidence of metastasis, prior pelvic radiotherapy or hormone therapy, prostate volume > 75 ml or American Society of Anesthesiology Risk class > 3 were excluded. The biochemical failure was based on the Phoenix criteria (PSA nadir + 2ng/dl). Patients were subjected for regular trans-rectal ultrasound and biopsy until 24 months of follow-up (at 3, 6, 12, 18, 24 months for CRYO and at 18, 24 months for EBRT) and then as clinically indicated. Biochemical disease-free survival (bDFS), disease-specific survival (DSS) and overall survival (OS) were analyzed with Kaplan-Meier curve.

Results: Sixty-two patients completed the trial with a median follow-up of 105.2 (± 35.8) months. Preoperative demographic and clinicopathological characteristics of both groups were comparable. All patients received neoadjuvant hormonal therapy for 3 months prior and continued for 3 months after the procedures. The prostate volume before the therapy was smaller in the CRYO group (31.3 ml vs 40.9 ml; p≤0.01). There was greater reduction in the prostate volume in the CRYO group after the intervention (–54% vs 34%; p≤0.01).Three patients in the cryotherapy arm and 2 patients in the radiotherapy arm were crossed over to the other modality at the time of biochemical or biopsy proven progression. The DSS and the OS were comparable between both groups. The 8-year bDFS rate was significant lower in the CRYO group (17.4% vs 59.1%; p=0.01).

Conclusions: This randomized trial showed that CRYO was suboptimal in attaining bDFS at 8 years in patients with locally advanced prostate cancer (cT3). Other recent randomized trial showed favorable outcome with CRYO for localized prostate cancer.

No significant financial relationships to disclose.

Robotic-assisted radical prostatectomy in a system of universal health care with limited access to high-tech resources

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Background: The goal of radical prostatectomy (RP) is to minimize the positive surgical margin (PSM) rate. Robotic- assisted radical prostatectomy (RALP) has the theoretical advantages of enhanced ability to identify surgical dissection planes to improve surgical outcome but is associated with a learning curve. The objective is to review the PSM rate and intra- and postoperative complications (Clavien grading) correlating with possible risk factors in a low-density RALP by a high-volume, open RP surgeon working in the Canadian Healthcare System.

Methods: The data of 56 RALP from April 2004 to Dec 2009 by one surgeon contemporaneously performed 830 RP. PSM was analyzed and correlated with clinical variables. Univariable and multivariable analyses were used.

Results: PSM 19 (34%) cases. At univariable analysis, no association was observed between PSM and age BMI, PSA, number positive cores, % positive cores, Gleason biopsy and clinical stage. Pathological Gleason (p=0.012), pathological stage (p= 0.003) and % tumor in surgical specimen (p=<0.001) were associated with increased risk of PSM. At multivariable the % tumor in surgical specimen (p<0.001) were only independent predictive factor for PSM. According to localization of PSM Apical 9 (48%), PLR 4 (21%), PLL 4 (21%) and bladder neck 1 (5%). Mean follow-up 23 months. In PSM, 12 (63%) showed an undetectable PSA (≤0.01ng/mL) at 3 months. Using Clavien grading, 9 surgical complication in 9(16%) patients: 6 (grade 1–2) and 3 (grade 3–4). 4 patients with PSM had complications, 2 (grade1-2) and 2 (grade 3–4). At multivariable analyses, BMI (p=0.008) was the only predictive factor for occurrence of complications.

Conclusions: The pathological stage and tumor (%) in the surgical specimen were independent predictive factor for PMS. Applying the Clavien grading, most of the patients presented minor complications. The Canadian Universal Healthcare system with limited access to high-tech resources may not be ideal for introducing an expensive new surgical technique, especially for an ubiquitous procedure such as RP. However, results of our low-density series or sporadic cases were not inferior to reported initial experience series of RALP in the literature.

No significant financial relationships to disclose.

Identification of caries risk factors in toddlers

The purpose of this study was to identify risk factors to predict caries progression in toddlers in primary-healthcare settings for the cost-effective targeting of preventive and referral strategies. We examined 329 children (26 ± 6 mos old) twice, one year apart, in Indiana, USA. A 107-item structured interview was used to collect information from the primary caregiver and child on factors/beliefs/perceptions/behaviors that could affect caries development, transmission of bacteria, medical-dental health, and access to care. Bacterial levels, gingivitis, dental plaque, and caries experience were assessed. Multiple-variable logistic regression models of caries progression toward cavitation included family caries experience, transmission-related behaviors, dietary factors, health beliefs, and lower income, but differed in selected predictors/predictive power by race/ethnicity. Addition of clinical variables did not significantly improve the prediction.

Audit of sudden deaths in the accident and emergency department of a tertiary hospital in Trinidad and Tobago

OBJECTIVE

To determine the proportion of deaths due to confirmed myocardial infarction (CMI) and the aetiology of sudden death at the Port-of-Spain General Hospital (A&E) department for January to June 2008.

METHODS

This retrospective study utilized the death register to determine the number of A&E deaths for the study period. Patients dying from MI were investigated using records to obtain ECG and postmortem reports.

RESULTS

During the study period, 150 patients were certified dead in the A&E department. Cardiovascular causes accounted for 42.7% (n = 64) of deaths. Confirmed MI accounted for 27.3% (n = 41) of deaths and 3.3% (n = 5) were certified by a private practitioner without post-mortem examination and were classed as unconfirmed MI. Trauma related deaths followed with 27.3% (n = 41). Deaths from firearm injury were the next most common, 19.3% (n = 29). The mean age of patients dying from CMI was 64.1 years with a male to female ratio of 2:1. Males died from CMI on average 6.3 years before females. Mortality peaked for females in the 80 - 89-year age group while for males it was the 60- 69-year age group. Afro-Trinidadians accounted for 58.5% (n = 24) deaths due to CMI. More CMI patients had combined DM and HTN 36.6% (n = 15) than either condition alone. Afro-Trinidadians were more likely to be hypertensive and Indo-Trinidadians, diabetic. Death on arrival was the most common presentation for MI patients, 65.9% (n = 27).

CONCLUSIONS

This study shows that the main cause of death in the A&E Department at the Port-of-Spain General Hospital was MI. Trauma related deaths followed. Men died from MI at an earlier age than women. Most MI patients were dead on arrival.

High-intensity focused ultrasound for prostate cancer: a systematic review

High-intensity focused ultrasound (HIFU) has recently been promoted as a non-invasive treatment option for prostate cancer. This systematic review sought to evaluate the evidence comparing it with standard treatment in patients with localised prostate cancer. The literature review included searches of MEDLINE, EMBASE, the Cochrane Library, annual meetings' abstracts and websites of evidence-based practice guideline producers. Studies were included if they were randomised controlled trials comparing HIFU with current management approaches, or were meta-analyses, systematic reviews or practice guidelines addressing HIFU. No randomised controlled trials or meta-analyses were identified. Seven systematic reviews and two practice guidelines were identified; neither contained randomised controlled trials. Adjusting the selection criteria to include case series found 34 clinical studies of HIFU. Twenty-nine evaluated HIFU as the primary treatment and five examined HIFU as salvage treatment for recurrence after radiotherapy. In most studies the outcomes used to determine efficacy were negative biopsy rates or prostate-specific antigen (PSA) levels. Among the 29 studies of HIFU as the primary treatment, negative biopsy rates ranged from 35 to 95% in 21 studies, a PSA nadir of ≤0.5 ng/ml ranged from 55 to 91% in 10 studies and mean PSA nadirs ranged from 0 to 1.9 ng/ml in 17 studies. Five studies reported 5-year disease-free survival rates ranging from 55 to 95%. Among five studies of HIFU as salvage treatment, negative biopsy rates ranged from 73 to 84% in four studies, a PSA nadir of ≤0.5 ng/ml ranged from 57 to 66% in three studies and mean PSA nadirs were 1.97 and 2.38 ng/ml in two studies, respectively. Current evidence on HIFU use in prostate cancer patients is of low quality, rendering it difficult to draw conclusions about its efficacy. Until results from case series are confirmed in prospective studies, the widespread use of HIFU is not supported.

Contemporary results of focal therapy for prostate cancer using cryotherapy

With the increasing diagnosis of prostate cancer, there have been concerns expressed regarding the potential over-treatment that may ensue following the diagnosis of localized prostate cancer. Minimally invasive treatments such as cryotherapy have been used successfully to treat the entire gland, however complications such as incontinence and erectile dysfunction can still occur. Focal cryotherapy is a modification of the standard cryotherapy technique, aiming to only treat the portion of the prostate gland which has the cancer of clinical significance. The potential advantage of this is the minimization of complications; however the remainder of the prostate is still viable and so can develop cancer subsequently. There have been several published studies demonstrating promising efficacy with a low morbidity rate using focal cryotherapy to treat prostate cancer, however further follow up is required before definitive conclusions can be reached. The appropriate selection of patients and subsequent follow up are areas needing further research and the development of improved imaging modalities.

Statistics of flexible chain configurations

When Monte Carlo methods are employed to study the statistical dimensions of flexible polymer chains, it is necessary that the sampling be statistically unbiased. One Monte Carlo procedure is the so-called "slithering snake" technique, which has proved to be very useful. A question arises, however, as to how long it takes for a "slithering snake" to be completely regenerated to avoid biasing the samples around a particular configuration. It is demonstrated theoretically and verified by Monte Carlo studies that the number of iterations required to completely regenerate a sample polymer is a quadratic function of the chain length. This verification applies to chains in dilute solution but may not hold for bulk polymers.