Validating a robust double-quantum-filtered (1) H MRS lactate measurement method in high-grade brain tumours.

(1) H MRS measurements of lactate are often confounded by overlapping lipid signals. Double-quantum (DQ) filtering eliminates lipid signals and permits single-shot measurements, which avoid subtraction artefacts in moving tissues. This study evaluated a single-voxel-localized DQ filtering method qualitatively and quantitatively for measuring lactate concentrations in the presence of lipid, using high-grade brain tumours in which the results could be compared with standard acquisition as a reference. Paired standard acquisition and DQ-filtered (1) H MR spectra were acquired at 3T from patients receiving treatment for glioblastoma, using fLASER (localization by adiabatic selective refocusing using frequency offset corrected inversion pulses) single-voxel localization. Data were acquired from 2 × 2 × 2 cm(3) voxels, with a repetition time of 1 s and 128 averages (standard acquisition) or 256 averages (DQ-filtered acquisition), requiring 2.15 and 4.3 min respectively. Of 37 evaluated data pairs, 20 cases (54%) had measureable lactate (fitted Cramér-Rao lower bounds ≤ 20%) in either the DQ-filtered or the standard acquisition spectra. The measured DQ-filtered lactate signal was consistently downfield of lipid (1.33 ± 0.03 ppm vs 1.22 ± 0.08 ppm; p = 0.002), showing that it was not caused by lipid breakthrough, and that it matched the lactate signal seen in standard measurements (1.36 ± 0.02 ppm). In the absence of lipid, similar lactate concentrations were measured by the two methods (mean ratio DQ filtered/standard acquisition = 1.10 ± 0.21). In 7/20 cases with measurable lactate, signal was not measureable in the standard acquisition owing to lipid overlap but was quantified in the DQ-filtered acquisition. Conversely, lactate was undetected in seven DQ-filtered acquisitions but visible using the standard acquisition. In conclusion, the DQ filtering method has proven robust in eliminating lipid and permits uncontaminated measurement of lactate. This is important validation prior to use in tissues outside the brain, which contain large amounts of lipid and which are often susceptible to motion.

Evaluation of lactate detection using selective multiple quantum coherence in phantoms and brain tumours.

Lactate is a product of glucose metabolism. In tumour tissues, which exhibit enhanced glycolytic metabolism, lactate signals may be elevated, making lactate a potential useful tumour biomarker. Methods of lactate quantitation are complicated because of overlap between the lactate methyl doublet CH3 resonance and a lipid resonance at 1.3 ppm. This study presents the use of a selective homonuclear multiple quantum coherence transfer sequence (SelMQC-CSI), at 1.5 T, to better quantify lactate in the presence of lipids. Work performed on phantoms showed good lactate detection (49%) and lipid suppression (98%) efficiencies. To evaluate the method in the brain, the sequence was tested on a group of 23 patients with treated brain tumours, either glioma (N=20) or secondary metastases in the brain (N=3). Here it was proved to be of use in determining lactate concentrations in vivo. Lactate was clearly seen in SelMQC spectra of glioma, even in the presence of lipids, with high grade glioma (7.3 ± 1.9 mM, mean ± standard deviation) having higher concentrations than low grade glioma (1.9 ± 1.5 mM, p=0.048). Lactate was not seen in secondary metastases in the brain. SelMQC-CSI is shown to be a useful technique for measuring lactate in tumours whose signals are otherwise contaminated by lipid.

Thoracic outlet syndrome in children and young adults.

OBJECTIVES: Thoracic outlet syndrome has been well described in the population between 25 and 40 years of age, and is less frequently reported in those in the first two decades of life. The objective of this study was to review results with onset of TOS in the first two decades of life to determine type of presentation and outcomes from surgical intervention. METHODS AND MATERIALS: Charts of all patients in the first two decades of life, operated on for TOS between 1994 and 2006 were reviewed with follow-up by clinic visit and phone survey to assess the patients' current level of activity and relief from symptoms. RESULTS: Twelve patients were identified (13 operations), with a mean age of 16.8 years. Acute ischemic symptoms were the initial presentation for 38%, venous TOS in 24%, and neurogenic symptoms in 38%. All patients had symptom relief with surgery with a mean time to resolution of 10.9 weeks. All patients remained symptom free or improved at follow-up. CONCLUSIONS: Vascular TOS is much more common in TOS presenting in the first two decades of life. Surgical intervention for TOS in this population results in long-lasting symptom relief and should be considered for all subtypes of patients.

The major low-molecular-weight heat shock protein in chloroplasts shows antigenic conservation among diverse higher plant species.

Several plant species are known to synthesize low-molecular-weight nucleus-encoded heat shock proteins (HSPs) which localize to chloroplasts. DNA sequence analysis of chloroplast HSP cDNAs from pea (Pisum sativum) and soybean (Glycine max) has shown that the carboxyl-terminal halves of these proteins are homologous to low-molecular-weight HSPs from a wide range of eucaryotes (E. Vierling, R. T. Nagao, A. E. DeRocher, and L. M. Harris, EMBO J. 7:575-581, 1988). We used a pea cDNA to construct fusion proteins containing either the carboxyl-terminal heat shock domain or the amino-terminal domain of the chloroplast HSP. The fusion proteins were overexpressed in Escherichia coli and used to produce choloroplast HSP-specific polyclonal antibodies. The carboxyl-terminal antibodies recognized chloroplast HSP precursor proteins from pea and from three divergent plant species, Arabidopsis thaliana, petunia (Petunia hybrida), and maize (Zea mays). The amino-terminal antibodies recognized effectively only the pea precursor. When intact plants of each species were subjected to a heat stress regime mimicking field growth conditions, significant levels of the mature forms of the chloroplast HSPs accumulated in pea, A. thaliana, and maize. The levels of accumulated HSPs remained unchanged for 12 h following the stress treatment. We conclude that the synthesis of chloroplast-localized HSPs is an important component of the stree response in all higher plants and that chloroplast HSPs from dicotyledonous and monocotyledonous plants have a conserved carboxyl-terminal domain.

Sleeping Beauty transposon screen identifies signaling modules that cooperate with STAT5 activation to induce B-cell acute lymphoblastic leukemia.

Signal transducer and activator of transcription 5 (STAT5) activation occurs frequently in human progenitor B-cell acute lymphoblastic leukemia (B-ALL). To identify gene alterations that cooperate with STAT5 activation to initiate leukemia, we crossed mice expressing a constitutively active form of STAT5 (Stat5b-CA) with mice in which a mutagenic Sleeping Beauty transposon (T2/Onc) was mobilized only in B cells. Stat5b-CA mice typically do not develop B-ALL (<2% penetrance); in contrast, 89% of Stat5b-CA mice in which the T2/Onc transposon had been mobilized died of B-ALL by 3 months of age. High-throughput sequencing approaches were used to identify genes frequently targeted by the T2/Onc transposon; these included Sos1 (74%), Kdm2a (35%), Jak1 (26%), Bmi1 (19%), Prdm14 or Ncoa2 (13%), Cdkn2a (10%), Ikzf1 (8%), Caap1 (6%) and Klf3 (6%). Collectively, these mutations target three major cellular processes: (i) the Janus kinase/STAT5 pathway (ii) progenitor B-cell differentiation and (iii) the CDKN2A tumor-suppressor pathway. Transposon insertions typically resulted in altered expression of these genes, as well as downstream pathways including STAT5, extracellular signal-regulated kinase (Erk) and p38. Importantly, expression of Sos1 and Kdm2a, and activation of p38, correlated with survival, further underscoring the role these genes and associated pathways have in B-ALL.

Vascular reactivity in patients with peripheral vascular disease.

Noninvasive techniques have been used to demonstrate a specific pattern of impaired vasoactive response in the normal brachial artery of patients with clinical atherosclerosis. This is a physiologic reflection of the systemic nature of atherosclerosis and may be useful as a marker for identifying patients with preclinical atherosclerotic disease.

Trisomy 18/trisomy 13 mosaicism in an adult with profound mental retardation and multiple malformations.

We report on an adult woman with profound mental retardation and multiple anomalies who consists of 3 cell lines: one with trisomy 18, one with trisomy 13, and a normal cell line. Her phenotype includes manifestations of both trisomy syndromes. The origin of these cell lines could have been a doubly aneuploid (48,XX + 13, + 18) or singly aneuploid (47,XX + 18 or 47,XX + 13) zygote with subsequent mitotic nondisjunctions, or a normal zygote with multiple mitotic nondisjunctions. There have been four previous reports of mosaicism involving both trisomy D and trisomy E; all died in the first six months of life. Two of these cases had a doubly aneuploid (48,XX, + D + E) cell line. Our patient illustrates the need for study of several tissues in patients with complex aneuploidy syndromes or atypical manifestations of a given syndrome (such as prolonged survival), as well as the need for caution in counseling families about prognosis for survival in autosomal trisomies which usually are lethal.

Isolated iliac artery aneurysms in patients with or without previous abdominal aortic aneurysm repair.

BACKGROUND: Isolated iliac artery aneurysms (IAA) in patients with or without previous abdominal aortic aneurysm (AAA) repair are rare. We wanted to compare the presentation, distribution, treatment, outcome and patterns of subsequent aneurysm formation in these patients. METHODS: We retrospectively reviewed patients with isolated IAA over a 10-year period. Patients with primary isolated IAA (group 1) were compared with patients who presented with IAA after previous AAA repair (group 2). RESULTS: There were 23 patients in each group. Demographics and comorbidities were similar. No aneurysms were detected outside of the iliac system in group 1; 22% of patients in group 2 had other aneurysms. The mean time after AAA repair to IAA diagnosis was 8.8 +/- 3.2 years for operated on patients. The in-hospital mortality was 0% for elective cases and 50% for emergency cases for both groups. Three patients in group 2 (13%) developed new aneurysms during follow-up, whereas the only new aneurysm in group 1 was a contralateral IAA. CONCLUSIONS: Patients with new IAA after AAA repair have a greater tendency to develop further aneurysms in other sites, synchronously or metachronously. The time to detection of new IAA after AAA repair is at least 5 years in most cases. In both groups, a quarter to a third of patients present with rupture, with a resultant mortality of 30% to 50%, whereas those operated on electively have minimal morbidity and almost no mortality.

Evidence for fear of restriction and fear of suffocation as components of claustrophobia.

Recent investigations of the aetiology and treatment of specific phobias have focused on clarifying the concerns underlying phobic anxiety. It has been proposed that claustrophobic fear is comprised of separable confinement and suffocation components. This paper presents data from 78 general medical outpatients undergoing magnetic resonance imaging (MRI) scans in two major teaching hospitals. The findings support the two factor structure of claustrophobia, in that exposure to confinement reduced confinement subscale scores, but did not influence suffocation scores.

The convergent validity of the Phobia Origins Questionnaire (POQ): a review of the evidence.

The Phobic Origins Questionnaire (POQ) [Ost, L.-G. & Hugdahl, K. (1981). Acquisition of phobias and anxiety response patterns in clinical patients. Behaviour Research and Therapy, 19, 439-447.] is the most commonly cited instrument for determining the origins of phobic anxiety and data obtained using this instrument strongly support the role of conditioning in the acquisition of fear reactions. The construct validity of the POQ in assessing episodes of conditioning has been questioned [e.g. Menzies, R. G. & Clarke, J. C. (1994). Retrospective studies of the origins of phobias: a review. Anxiety, Stress and Coping, 7, 305-318.] This paper examined the convergent validity of the POQ by comparing origins' classifications based on the POQ to classifications based on alternative instruments. The convergent validity of the POQ was found to be extremely poor. The POQ was consistently associated with a much greater likelihood of classifying the origin of fear reactions as due to direct conditioning episodes than was found using alternative instruments. The findings question the usefulness of the POQ in examining the origins of phobic anxiety.

The relationship between inflated personal responsibility and exaggerated danger expectancies in obsessive-compulsive concerns.

The association between responsibility for a negative outcome, perceived severity of the outcome and perceived likelihood of the outcome was examined in a sample of 70 undergraduate students. Participants were asked to rate the likelihood and severity of 10 negative outcomes, five related to contamination and five related to checking. Thirty-eight participants completed a version of the questionnaire that presented the subject as responsible for the action that may lead to a negative outcome ('personally responsible' group). The remaining 32 completed a version of the questionnaire that presented someone else performing the actions that may lead to a negative outcome ('other responsible' group). Significant differences emerged between the personally responsible and other responsible groups for severity of outcome ratings but not for likelihood of outcome ratings. Specifically, for both washing and checking concerns, participants in the personally responsible group rated the severity of the potential negative outcome as greater than did those in the other responsible group. The results support the claimed general tendency for individuals to regard an outcome as more aversive if they are personally responsible for that outcome, rather than someone else being responsible. The results suggest that, in general, increasing perceptions of personal responsibility will increase cost or severity estimates in subjective danger calculations, and that responsibility may influence OCD phenomena in this way. Finally, the results suggest that attempts to manipulate responsibility in the laboratory may be confounded by necessarily impacting on cost estimates, and therefore on danger expectancies.

Establishment of conditions for the detection of bovine herpesvirus-1 by polymerase chain reaction using primers in the thymidine kinase region.

Polymerase chain reaction (PCR) for detection of bovine herpesvirus-1 (BHV-1) was developed and optimized using 22 bp sense and 20 bp antisense primers in the thymidine kinase (TK) coding region. The amplification product is 183 bp long. The PCR optimization was done using BHV-1 tissue culture supernate (BHV-1TCS), concentrated BHV-1 tissue culture supernate (cBHV-1TCS) and sucrose gradient purified BHV-1 (pBHV-1). The sensitivity of four methods of sample preparation which are standard DNA extraction, modified proteinase K (PK) digestion, GeneReleaserTM + 34 cycles or + 44 cycles, and boiling were compared with virus isolation (VI) using BHV-1TCS. The incorporation of 10% glycerol in the reaction mixture, the incubation in PK for 18 hours and predenaturation of samples and cooling in ice prior to PCR were essential for the amplification of BHV-1 DNA for samples prepared by standard DNA extraction and modified PK digestion. The preparation of samples by Gene-ReleaserTM, a proprietary nucleic acid releasing cocktail, showed 10 to 1,000-fold increase in sensitivity compared to standard DNA extraction and modified PK digestion. No amplification was observed in samples prepared by boiling. The sample preparation of BHV-1 LA strain by GeneReleaserTM showed sensitivity equivalent to virus isolation. The BHV-1 TK PCR using GeneReleaserTM has a detection limit of 1 picogram and 10 fentograms of purified BHV-1 DNA using ethidium bromide stained gel and Southern blot hybridization, respectively. It could detect viral DNA in 1,000 infected cells in a total suspension of 10,000 cells using either ethidium bromide stained gel or Southern blot hybridization.

Amplification of strains of bovine herpesvirus 1 by use of polymerase chain reaction with primers in the thymidine kinase region.

A primer pair was designed from the published nucleotide sequence of the coding region of the bovine herpesvirus 1 (BHV-1) thymidine kinase (tk) gene for use in detection of the virus by use of polymerase chain reaction (PCR) amplification of 12 BHV-1 strains (3 ATCC and 9 local isolates). A tk deletion mutant BHV-1, and 2 BHV-4 strains from ATCC were used as negative controls. One strain each of feline herpes-virus, equine herpesvirus, and bovine adenovirus, and 2 noninoculated bovine cultured cells--bovine fetal testis and Madin-Darby bovine kidney--also were examined to verify specificity of the primers. A PCR product, 183 bp long, was detected by ethidium bromide staining after agarose gel electrophoresis, when purified DNA from cell cultures infected with BHV-1 strain LA was used as template. Specificity of the PCR product was confirmed by restriction digestion with Sac II enzyme and Southern blot hybridization. Amplification was detected by ethidium bromide staining of agarose gels and/or Southern blot hybridization with the radiolabeled PCR product of the LA strain in similarly prepared DNA templates of 5 other BHV-1 strains, 2 obtained from ATCC and 3 of the 9 local isolates. In a modified PCR protocol, using virus suspensions treated with a nucleic acid-releasing cocktail, substantial amplification was obtained for the 3 BHV-1 strains from ATCC and for all 9 local bovine herpesvirus field isolates.(ABSTRACT TRUNCATED AT 250 WORDS)

Health science graduates: preparation for the workplace.

The research reported in this article was undertaken to assess the perceptions of health science graduates in the fields of health information management, occupational therapy, orthoptics, physiotherapy, and speech pathology regarding their perceptions of the adequacy of undergraduate preparation in meeting the demands of a changing health care environment. An instrument was devised for use by graduates on the basis of the skills and workplace behaviours specified by experienced practitioners in the above fields as necessary in newly recruited graduates. A total of 527 health science graduates completed the 52 item instrument. The statistical analyses indicated that 11 factors define the adequacy of graduates' preparation for the workplace. Health science graduates perceived themselves to have been more thoroughly prepared on certain workplace dimensions than on others. Specifically, graduates perceived themselves to be ill-equipped on dimensions concerned with workplace management, knowledge of the health industry, and coping in the workplace. Graduates also perceived themselves to be inadequately prepared in terms of communicating with clients, health professionals, and the general public. The strengths of their courses were perceived to be in completing essential tasks, having confidence in the clinical role, in ethical practice, in pursuit and application of knowledge, and having a realistic expectation of the workplace role. The results are discussed in terms of the need to address curriculum changes.

Impact of curricular change in an undergraduate program for speech pathologists on perceived preparedness for the workplace.

Recently, educational policymakers have emphasized the need for undergraduate programs to develop in their graduates generic skills and attributes beyond discipline-specific skills and knowledge. The generic skills and attributes should mesh with the requirements of the workplaces where the graduates will find employment. The present study examined the impact of curricular revisions to a program of study for speech pathologists on the perceptions of the graduates regarding their preparation in appropriate skill and knowledge domains. The curricular revisions sought to develop independent learning, critical thinking, research and evaluation skills, written and oral communication skills, and skills for seeking and providing support to peers. Seventy-eight graduates of the earlier program and 21 graduates of the revised program offered by the School of Communication Disorders at The University of Sydney completed a 52-item questionnaire concerning the extent to which the program had equipped them for the workplace. Eleven scales were derived from the questionnaire responses, reflecting skills endorsed by university educators and workplace supervisors of allied health professionals as being necessary for success in the workplace. The relative levels of perceived preparation on the 11 dimensions were similar across graduates of the revised program and those of the earlier program. Graduates of the revised program were significantly more positive about their preparation on five of the 11 dimensions, compared with earlier graduates of approximately equivalent age and experience. The dimensions where differences were observed generally reflected those targeted by the curricular revisions.

The relationship between cognitive function and clinical and functional outcomes in major depressive disorder.

BACKGROUND: Although cognitive variables have been shown to be useful in predicting outcomes in late-life depression, there has not yet been a comprehensive study in younger persons with depression. METHOD: The clinical symptoms and cognitive performance of participants were evaluated at admission to one of two university teaching hospitals and again at 3 months after remission and discharge. A total of 52 participants with a DSM-IV diagnosis of major depressive disorder, aged between 20 and 60 years and with a Hamilton Depression Rating Scale score 17 > or = entered the study. The sample for this paper comprises the 48 subjects (mean age 37.9 years, s.d.=10.7) who received admission and follow-up assessments; an attrition rate of 7.7%. RESULTS: More perseverative errors on the shortened Wisconsin Card Sorting Test at admission predicted a worse clinical outcome at follow-up. Poor event-based prospective memory and more perseverative errors on the shortened Wisconsin Card Sorting Test at admission predicted worse social and occupational outcome at follow-up. CONCLUSIONS: These results suggest that a brief cognitive screen at hospital admission, focusing on executive function, would have a useful prognostic value in depression. Determining early predictors of individuals at risk of poorer outcomes is important for identifying those who may need altered or additional treatment approaches.

Identification and characterisation of childhood cerebellar tumours by in vivo proton MRS.

(1)H MRS has great potential for the clinical investigation of childhood brain tumours, but the low incidence in, and difficulties of performing trials on, children have hampered progress in this area. Most studies have used a long-TE, thus limiting the metabolite information obtained, and multivariate analysis has been largely unexplored. Thirty-five children with untreated cerebellar tumours (18 medulloblastomas, 12 pilocytic astrocytomas and five ependymomas) were investigated using a single-voxel short-TE PRESS sequence on a 1.5 T scanner. Spectra were analysed using LCModel to yield metabolite profiles, and key metabolite assignments were verified by comparison with high-resolution magic-angle-spinning NMR of representative tumour biopsy samples. In addition to univariate metabolite comparisons, the use of multivariate classifiers was investigated. Principal component analysis was used for dimension reduction, and linear discriminant analysis was used for variable selection and classification. A bootstrap cross-validation method suitable for estimating the true performance of classifiers in small datasets was used. The discriminant function coefficients were stable and showed that medulloblastomas were characterised by high taurine, phosphocholine and glutamate and low glutamine, astrocytomas were distinguished by low creatine and high N-acetylaspartate, and ependymomas were differentiated by high myo-inositol and glycerophosphocholine. The same metabolite features were seen in NMR spectra of ex vivo samples. Successful classification was achieved for glial-cell (astrocytoma + ependymoma) versus non-glial-cell (medulloblastoma) tumours, with a bootstrap 0.632 + error, e(B.632+), of 5.3%. For astrocytoma vs medulloblastoma and astrocytoma vs medulloblastoma vs ependymoma classification, the e(B.632+) was 6.9% and 7.1%, respectively. The study showed that (1)H MRS detects key differences in the metabolite profiles for the main types of childhood cerebellar tumours and that discriminant analysis of metabolite profiles is a promising tool for classification. The findings warrant confirmation by larger multi-centre studies.

Intravenous leiomyomatosis with cardiac extension: tumor thrombectomy through an abdominal approach.

Intravenous leiomyomatosis is an uncommon vascular tumor that may be seen with potentially life-threatening symptoms resulting from intracardiac extension. This tumor is frequently misdiagnosed and treated without appropriate preoperative imaging and planning, which at times leads to inadequate treatment and incomplete resections. The appropriate therapy is complete excision of the tumor. We describe a patient who was treated with a new approach involving a single-stage operation without the need for median sternotomy, cardiopulmonary bypass graft, or hypothermic arrest by resection of the tumor from the point of attachment in the abdominal portion of the inferior vena cava.