Transduction of umbilical cord blood CD34+ NOD/SCID-repopulating cells by simian foamy virus type 1 (SFV-1) vector

Foamy viruses are nonpathogenic retroviruses that offer unique opportunities for gene transfer into various cell types including hematopoietic stem cells. We used a simian foamy virus type 1 vector (SFV-1) containing a LacZ reporter gene with a titer of 1-5 x 10(6) viral particles/ml that was free of replication-competent retrovirus to transduce human umbilical cord blood CD34+ cells. Transduced CD34+ cord blood cells were transplanted into NOD/SCID mice and plated in serum-free methylcellulose culture to determine the transduction efficiency of human hematopoietic progenitor cells. A transduction efficiency of about 20% was obtained. At 6-10 weeks posttransplantation, human hematopoietic cell engraftment and marking were determined. Marrow from transplanted mice demonstrated human cell engraftment by the presence of human (CD45+) cells containing both CD19+ lymphoid and CD33+ myeloid cells. Serial sampling of NOD/SCID bone marrow revealed the presence of 6.7-14.0% CD45+ cells at 6 weeks posttransplant as compared to 3.6-27.2% CD45+ cells at 9-10 weeks posttransplant. Human progenitors examined from NOD/SCID bone marrow cells 9 weeks posttransplant revealed from 7.4 to 25.9% of the colonies exhibiting X-gal staining. Our study demonstrates the ability of a simian foamy virus vector to transduce the SCID-repopulating cell and offers a promising new gene delivery system for use in hematopoietic stem cell gene therapy.     

Telepathology for routine light microscopic and frozen section diagnosis

Telepathology (TP) uses telecommunication linkages to electronically capture, store, retrieve, and transmit images to distant sites. We assessed the feasibility of a dynamic real-time TP system for light microscopic (LM) diagnosis of anatomic pathology specimens, including frozen sections. Six pathologists, in 2 separate periods, read a set of 160 retrospectively retrieved slides (80 of which were frozen sections) by TP and LM. Reading times were recorded. Diagnoses were compared with the reference diagnosis (established by a group of 5 independent pathologists) and graded on a scale of 0 to 2 (2, correct; 1, incorrect but no clinical impact; 0, incorrect with clinical impact). Overall, LM was more accurate than TP compared with the reference diagnosis (score, 1.68 vs 1.54). There was no difference in accuracy between frozen section and paraffin-embedded tissue. Intraobserver agreement ranged from 82.5% to 88.2%. The average reading time was 6.0 minutes for TP and 1.4 minutes for LM. During the study, reading time decreased for TP but not for LM. These results show that despite marginally lower accuracy and longer reading times, TP isfeasible for routine light microscopic diagnosis, including frozen sections.     

Assessing the optimal preparation strategy to minimize the variability of cardiac pyruvate dehydrogenase flux measurements with hyperpolarized MRS

Hyperpolarized [1‐¹³C] pyruvate MRS can measure cardiac pyruvate dehydrogenase (PDH) flux in vivo through ¹³C‐label incorporation into bicarbonate. Using this technology, substrate availability as well as pathology have been shown to modulate PDH flux. Clinical protocols attempt to standardize PDH flux with oral glucose loading prior to scanning, while rodents in preclinical studies are usually scanned in the fed state. We aimed to establish which strategy was optimal to maximize PDH flux and minimize its variability in both control and Type II diabetic rats, without affecting the pathological variation being assessed. We found similar variances in the bicarbonate to pyruvate ratio, reflecting PDH flux, in fed and fasted/glucose‐loaded animals, which showed no statistically significant differences. Furthermore, fasting/glucose loading did not alter the low PDH flux seen in Type II diabetic rats. Overall this suggests that preclinical cardiac hyperpolarized magnetic resonance studies could be performed either in the fed or in the fasted/glucose‐loaded state. Centres planning to start new clinical studies with cardiac hyperpolarized magnetic resonance in man may find it beneficial to run small proof‐of‐concept trials to determine whether metabolic standardizations by oral or intravenous glucose load are beneficial compared with scanning patients in the fed state.     

How nonclinical are community samples?

Mental health services are underutilized in our society by both adults and children. This finding presents a potential problem for researchers conducting community‐based research. Previous studies have demonstrated that community‐based researchers frequently do not screen participants for the presence of psychopathology nor do they ascertain whether therapeutic services are currently utilized. The present study explored the prevalence of psychopathology and treatment involvement in a sample of families recruited from the community. Results indicated that a fifth of the participants in this community‐based sample met diagnostic criteria for a psychiatric disorder or were in treatment for psychological difficulties at the time of recruitment for this study. Furthermore, mothers, fathers, and adolescents who met the criteria according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM‐IV; American Psychiatric Association, 1994 ) for a psychological disorder had higher symptomatology than those who did not meet criteria. Methodological suggestions are provided. © 2008 Wiley Periodicals, Inc.     

Determination and application of immunodominant regions of SARS coronavirus spike and nucleocapsid proteins recognized by sera from different animal species

Knowledge of immunodominant regions in major viral antigens is important for rational design of effective vaccines and diagnostic tests. Although there have been many reports of such work done for SARS-CoV, these were mainly focused on the immune responses of humans and mice. In this study, we aim to search for and compare immunodominant regions of the spike (S) and nucleocapsid (N) proteins which are recognized by sera from different animal species, including mouse, rat, rabbit, civet, pig and horse. Twelve overlapping recombinant protein fragments were produced in Escherichia coli, six each for the S and N proteins, which covered the entire coding region of the two proteins. Using a membrane-strip based Western blot approach, the reactivity of each antigen fragment against a panel of animal sera was determined. Immunodominant regions containing linear epitopes, which reacted with sera from all the species tested, were identified for both proteins. The S3 fragment (aa 402-622) and the N4 fragment (aa 220-336) were the most immunodominant among the six S and N fragments, respectively. Antibodies raised against the S3 fragment were able to block the binding of a panel of S-specific monoclonal antibodies (mAb) to SARS-CoV in ELISA, further demonstrating the immunodominance of this region. Based on these findings, one-step competition ELISAs were established which were able to detect SARS-CoV antibodies from human and at least seven different animal species. Considering that a large number of animal species are known to be susceptible to SARS-CoV, these assays will be a useful tool to trace the origin and transmission of SARS-CoV and to minimise the risk of animal-to-human transmission.     

Human growth hormone 1 (GH1) gene expression: complex haplotype-dependent influence of polymorphic variation in the proximal promoter and locus control region

The proximal promoter region of the human pituitary expressed growth hormone (GH1) gene is highly polymorphic, containing at least 15 single nucleotide polymorphisms (SNPs). This variation is manifest in 40 different haplotypes, the high diversity being explicable in terms of gene conversion, recurrent mutation, and selection. Functional analysis showed that 12 haplotypes were associated with a significantly reduced level of reporter gene expression whereas 10 haplotypes were associated with a significantly increased level. The former tend to be more prevalent in the general population than the latter (p<0.01), possibly as a consequence of selection. Although individual SNPs contributed to promoter strength in a highly interactive and non-additive fashion, haplotype partitioning was successful in identifying six SNPs as major determinants of GH1 gene expression. The prediction and functional testing of hitherto unobserved super-maximal and sub-minimal promoter haplotypes was then used to test the efficacy of the haplotype partitioning approach. Electrophoretic mobility shift assays demonstrated that five SNP sites exhibit allele-specific protein binding. An association was noted between adult height and the mean in vitro expression value corresponding to an individual's GH1 promoter haplotype combination (p=0.028) although only 3.3% of the variance of adult height was found to be explicable by reference to this parameter. Three additional SNPs, identified within sites I and II of the upstream locus control region (LCR), were ascribed to three distinct LCR haplotypes. A series of LCR-GH1 proximal promoter constructs were used to demonstrate that 1) the LCR enhanced proximal promoter activity by up to 2.8-fold depending upon proximal promoter haplotype, and that 2) the activity of a given proximal promoter haplotype was also differentially enhanced by different LCR haplotypes. The genetic basis of inter-individual differences in GH1 gene expression thus appears to be extremely complex.     

High dimensional analysis reveals distinct NK cell subsets but conserved response to stimulation in umbilical cord blood and adult peripheral blood

Growing interest surrounds adoptive cellular therapies utilizing Natural Killer (NK) cells, which can be obtained from various sources, including umbilical cord blood (UCB) and adult peripheral blood (APB). Understanding NK cell receptor expression and diversity in such cellular sources will guide future therapeutic designs. We used a 20-color flow cytometry panel to compare unstimulated and cytokine-activated UCB and APB NK cells. Our analysis showed that UCB NK cells express slightly higher levels of the immune checkpoints PD-1, TIGIT, and CD96 compared to their APB counterparts. Unsupervised hierarchical clustering and dimensionality reduction analyses revealed enrichment in CD56^neg as well as mature NKp46^neg and CD56⁺CD16⁺ NK cell populations in UCB whereas CD57⁺ terminally differentiated NK cells with variable expression of KIRs and CD16 were found in APB. These populations were conserved following stimulation with IL-12, IL-15, and IL-18. Cytokine stimulation was associated with the downregulation of TIGIT and CD16 on multiple NK cell subsets in UCB and APB. Among UCB CD16⁻ NK cell populations, TIGIT⁺ NK cells produced more IFN-γ than their TIGIT⁻ counterparts. Our data demonstrate higher immune checkpoint expression on UCB NK cells compared to APB. However, the expression of TIGIT immune checkpoint is not indicative of NK cell exhaustion.     

Temsirolimus with or without megestrol acetate and tamoxifen for endometrial cancer: A gynecologic oncology group study

Objectives

To determine the response, toxicities, and progression free survival of a regimen of temsirolimus with or without hormonal therapy in the treatment of advanced, or recurrent endometrial carcinoma.

Background

Preclinical evidence suggested that blockade of the PI3K/AKT/mTOR pathway might overcome resistance to hormonal therapy.

Methods

We performed a randomized phase II trial of intravenous temsirolimus 25 mg weekly versus the combination of weekly temsirolimus with a regimen of megestrol acetate 80 mg bid for three weeks alternating with tamoxifen 20 mg bid for three weeks in women with recurrent or metastatic endometrial carcinoma.

Results

There were 71 eligible patients who received at least one dose of therapy with 21 of these treated on the combination arm which was closed early because of an excess of venous thrombosis, with 5 episodes of deep venous thrombosis (DVT) and 2 pulmonary emboli. There were three responses observed in that arm (14%). A total of 50 eligible patients were treated on the single agent arm with 3 episodes of DVT and 11 responses (22%). Response rates were similar in patients with prior chemotherapy (7 of 29; 24%) and those with no prior chemotherapy (4 of 21; 19%). Two of four patients with clear cell carcinoma responded.

Conclusions

Adding the combination of megestrol acetate and tamoxifen to temsirolimus therapy did not enhance activity and the combination was associated with an excess of venous thrombosis. Temsirolimus activity was preserved in patients with prior adjuvant chemotherapy.     

A lentivirally delivered photoactivatable GFP to assess continuity in the endoplasmic reticulum of neurones and glia

The endoplasmic reticulum (ER) is the largest intracellular membranous organelle. Functions of the ER are many and diverse, which include various biosynthetic, transport and signalling roles, central to cellular physiology, such as the biosynthesis of membrane and secretory proteins and the regulation of intracellular calcium. Its continuous lumen also serves as a highway for the distribution of proteins and ions to different regions of the cell, independent of the cytosol. The ER is an excitable organelle, capable of generating a regenerative wave of calcium release, which can propagate along the endomembrane throughout the entire cell, serving as a system of intracelluar communication in polarised cells. Nowhere is this feature of ER function more crucial than in neurones. The extremely polarised nature of nerve cells presents a unique challenge for the global co-ordination of localised physiological events such as growth cone guidance and synaptic plasticity. Clearly, the physical continuity of the neuronal ER lumen is central to its functionality as a conduit for communication. To further probe the continuity of ER in neurones and glia, we developed LV-PA-pIN-KDEL, a photoactivatable analogue of our recently described vector LV-pIN-KDEL, a lentivirally delivered ER-targeting soluble GFP. We demonstrate the ability of this vector to transduce astrocytes and neurones in culture and in cortical explants. Furthermore, we exploit the photoactivatable attributes of the vector together with a focal laser photoactivation protocol to reveal the continuous nature of the ER lumen in these cell types, presenting the first direct evidence of an astrocytic ER luminal continuum and providing more data to support the existence of a single ER lumen in neurones. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Hepatitis B awareness,knowledge, and screening among Asian Americans

BACKGROUND: Due to the high prevalence of hepatitis B, Asian Americans have high rates of liver cancer. Screening for hepatitis B leads to monitoring and treatment and prevent further infection through vaccination of contacts. METHODS: We reviewed the published literature up to 2006 on hepatitis B awareness, knowledge, and screening among Asian Americans. RESULTS: Many Asian Americans lack knowledge about hepatitis B and have not been screened. Sociodemographics, knowledge, beliefs, and health care variables are associated with screening. CONCLUSIONS: Further research and health policy changes are needed to address the problem of hepatitis B and liver cancer among Asian Americans.