Optimizing multiphoton fluorescence microscopy light collection from living tissue by noncontact total emission detection (epiTED)

A benefit of multiphoton fluorescence microscopy is the inherent optical sectioning that occurs during excitation at the diffraction-limited spot. The scanned collection of fluorescence emission is incoherent; that is, no real image needs to be formed on the detector plane. The nearly isotropic emission of fluorescence excited at the focal spot allows for new detection schemes that efficiently funnel all attainable photons to detector(s). We previously showed [Combs, C.A., et al. (2007) Optimization of multiphoton excitation microscopy by total emission detection using a parabolic light reflector. J. Microsc. 228, 330-337] that parabolic mirrors and condensers could be combined to collect the totality of solid angle around the excitation spot for tissue blocks, leading to ∼8-fold signal gain. Using a similar approach, we have developed an in vivo total emission detection (epiTED) instrument modified to make noncontact images from outside of living tissue. Simulations suggest that a ∼4-fold enhancement may be possible (much larger with lower NA objectives than the 0.95 NA used here) with this approach, depending on objective characteristics, imaging depth and the characteristics of the sample being imaged. In our initial prototype, 2-fold improvements were demonstrated in the mouse brain and skeletal muscle as well as the rat kidney, using a variety of fluorophores and no compromise of spatial resolution. These results show this epiTED prototype effectively doubles emission signal in vivo; thus, it will maintain the image signal-to-noise ratio at two times the scan rate or enable full scan rate at approximately 30% reduced laser power (to minimize photo-damage).

Regulation of p53 expression, phosphorylation and subcellular localization by a G-protein-coupled receptor

G-protein coupled receptors (GPCRs) have been extremely successful drug targets for a multitude of diseases from heart failure to depression. This super-family of cell surface receptors have not, however, been widely considered as a viable target in cancer treatment. In the current study we demonstrate that a classical G_q/11-coupled GPCR, the M₃-muscarinic receptor, was able to regulate apoptosis via receptors that are endogenously expressed in the human neuroblastoma cell line SH-SY5Y and when ectopically expressed in Chinese hamster ovary (CHO) cells. Stimulation of the M₃-muscarinic receptor was shown to inhibit the ability of the DNA-damaging chemotherapeutic agent, etoposide, from mediating apoptosis. This protective response in CHO cells correlated with the ability of the receptor to regulate the expression levels of p53. In contrast, stimulation of endogenous muscarinic receptors in SH-SY5Y cells did not regulate p53 expression but rather was able to inhibit p53 translocation to the mitochondria and p53 phosphorylation at serine 15 and 37. This study suggests the possibility that a GPCR can regulate the apoptotic properties of a chemotherapeutic DNA-damaging agent by regulating the expression, sub-cellular trafficking and modification of p53 in a manner that is in part dependent on the cell type.

A novel method for isolation of human lung T cells from lung resection tissue reveals increased expression of GAPDH and CXCR6

Lung T lymphocytes are important in pulmonary immunity and inflammation. It has been difficult to study these cells due to contamination with other cell types, mainly alveolar macrophages. We have developed a novel method for isolating lung T cells from lung resection tissue, using a combination of approaches. Firstly the lung tissue was finely chopped and filtered through a nylon mesh. Lymphocytic cells were enriched by Percoll density centrifugation and the T cells purified using human CD3 microbeads, resulting in 90.5%+/-1.9% (n=11) pure lymphocytes. The T cell yield from the crude cell preparation was 10.8+/-2.1% and viability, calculated using propidium iodide (PI) staining and trypan blue, was typically over 95%. The purification process did not affect expression of CD69 or CD103, nor was there a difference in the proportion of CD4 and CD8 cells between the starting population and the purified cells. Microarray analysis and real time RT-PCR revealed upregulation of GAPDH and CXCR6 of the lung T cells as compared to blood-derived T cells. This technique highly enriches lung T cells to allow detailed investigation of the biology of these cells.

The incidence of adverse reactions following 4% septocaine (articaine) in children

PURPOSE

The purpose of this study was to report the incidence of adverse events following the use of 4% Septocaine in children.

METHODS

A prospective study was carried out on children attending university-based pediatric dental clinics for restorative core under local anesthesia. Data collection included patient demographics, medical history, amount and site of injection, and treatment complexity. Follow-up telephone interviews were conducted with the parents at 3, 5, 24, and 48 hours regarding prolonged paresthesia, soft tissue injury, and pain.

RESULTS

Two hundred sixty-four 2 to 14 year-olds were recruited for the study. Complete interview information was obtained from 204 patients. Prolonged paresthesia at 3 hours postinjection was reported for 40% of the population and at 5 hours for 11%. Soft tissue injury occurred in 14% of the patients at 3 hours and was found to be highest among children younger than 7 years old. The lip was the most commonly affected site for accidental injury and it was not related to injection site. Twenty percent reported postprocedural pain at 3 and 5 hours post-treatment.

CONCLUSIONS

Since prolonged numbness appears to be the most frequent adverse event and occurred primarily in children younger than 7 years old, parents need to be informed and reassured accordingly.

Apoptosis induced by histone deacetylase inhibitors in leukemic cells is mediated by Bim and Noxa

Several histone deacetylase inhibitors (HDACi), which have recently entered early clinical trials, exert their anticancer activity in part through the induction of apoptosis although the precise mechanism of this induction is not known. Induction of apoptosis by structurally diverse HDACi in primary cells from patients with chronic lymphocytic leukemia (CLL) and different leukemic cell lines was mediated by the Bcl-2 regulated intrinsic pathway and demonstrated a requirement for de novo protein synthesis. A marked time-dependent induction of the pro-apoptotic BH3-only proteins, Bim, Noxa and Bmf was observed, which preceded the induction of apoptosis. A key role for both Bim and Noxa was proposed in HDACi-mediated apoptosis based on our findings that siRNA for Bim and Noxa but not Bmf largely prevented the HDACi-induced loss in mitochondrial membrane potential, caspase processing and phosphatidylserine externalization. Noxa, induced by HDACi, in CLL cells and tumor cell lines, bound extensively to Mcl-1, a major anti-apoptotic Bcl-2 family member present in CLL cells. Our data strongly suggests that HDACi induce apoptosis primarily through inactivation of anti-apoptotic Bcl-2 family members by increases in Bim and Noxa and highlights these increases as a potential clinical target for CLL/lymphoma therapy.

FOXP3 is a homo-oligomer, and it interactions with histone acetyltransferase and class II histone deacetylases are required for repression (88.30)

We have found that FOXP3 is an oligomeric component of a large supramolecular complex. The Zinc-Leuzip region of FOXP3 is sufficient to mediate its homotetramerization. Wild type FOXP3 directly binds to the human IL-2 promoter, but the E251 deletion in FOXP3 in XLAAD/IPEX patient’s T cells disrupts its homo-oligomerization, heteromerization with FOXP1, its association with the IL-2 promoter, and limits repression of IL-2 transcription after T cell activation. Additionally we report that transcriptional repression by FOXP3 involves a histone acetylase-deacetylase complex that includes TIP60 and HDAC7 and HDAC9. FOXP3 can be acetylated, and TIP60 promotes FOXP3 acetylation in vivo. Knockdown of endogenous TIP60 relieved FOXP3-mediated transcriptional repression. A minimum FOXP3 ensemble containing native TIP60 and HDAC7 is necessary for IL-2 production regulation in T cells. Moreover, FOXP3 association with HDAC9 is antagonized by T cell stimulation, and can be restored by the Trichostatin A indicating a complex dynamic aspect of T suppressor cell regulation. These findings identify a novel complex based mechanism by which FOXP3 actively mediates transcriptional repression.

Expansion of Functional Polyclonal Human T-regulatory Cell Lines Using Artificial Antigen Presenting Cells and Rapamycin. (B159)

T-regulatory CD4+CD25+ T lymphocytes play a central role in regulating immune response and preventing autoimmunity. There is a broad spectrum of potential clinical applications of expanded T-regs including but not limited to treatments of graft versus host disease, transplant rejection, and type I diabetes.

K562 cell line with stable expression of lentivirus-introduced CD64 and CD86 markers (KT64/86) and loaded with anti-CD3 antibodies was used to expand human CD4+CD25 high T lymphocytes. Though in several occasions stimulation of CD4+CD25high cells with KT64/86 only resulted in production of functional T-regulatory cells, only when antibiotic rapamycin was added to the cultures, functional Tregs were produced in 100% of stimulations. These cells were also active in vivo in reversing GVHD in NOG mice. Total CD4 lymphocytes grown in the presence of rapamycin though suppressive in vitro were not able to reverse GVHD in mice.

Substitution of CD86 with CD80 resulted in a less potent Tregs. Addition of certain members of TNF receptor family such as CD70, OX40 ligand or 4-1BB ligand to KT64/86 cells, had different effects on expansion of Treg cell lines. While CD70 addition did not show any impact, 4-1BB and OX-40 ligands in most cases stimulated growth of T-regulatory cell lines but at the same time in most cases also attenuated their activity.

The project is supported by JDRF Collaborative Center for Cell Therapy grant to C.J.

The significance of post-traumatic amnesia as a risk factor in the development of olfactory dysfunction following head injury

OBJECTIVE

To test the following hypothesis in the assessment of head injury

PATIENTS

only patients with 5 min or more of post-traumatic amnesia (PTA) are at risk of acute olfactory dysfunction (OD).

METHODS

This was a retrospective comparative study of olfactory status in head injury patients seen at a head injury clinic at Glasgow Royal Infirmary from 1985 to 2003. Of 828 clinic attenders, 101 had acute OD. These subjects were compared with a randomly selected control group of 102 patients with head injury but normal olfactory function. The main outcome measure was a significant likelihood of patients with PTA lasting for 5 or more minutes having acute OD compared with those with PTA of less than 5 min.

RESULTS

The likelihood of patients with a PTA of 5 min or more having acute OD compared to those with PTA of less than 5 min is clinically significant with an odds ratio of 9.6 (p<0.01).

CONCLUSION

Examination of patients with 5 min or more of PTA should include a simple test of sense of smell. Patients with impaired smell sensation should be aware of their condition prior to discharge from hospital. In addition, the need for a CT brain scan and appropriate follow up should be considered.

Ethical aspects of palliative care in lung cancer and end stage lung disease

Over 50 000 people die per year in England and Wales from lung cancer and chronic obstructive pulmonary disease (COPD). Current National Institute for Clinical Evidence guidelines for lung cancer and COPD recommend provision of palliative care for those that need it. Palliative care historically has accepted patients with cancer, but access to patients with non-malignant disease has been more sporadic. This paper aims to highlight the many ethical dilemmas faced when treating both these groups of patients. These include issues surrounding the form of treatment or treatment withdrawal, the burden on the patient or on the health service; or conducting research in terminally ill patients.

Gabapentin is Effective in the Treatment of Cancer-Related Neuropathic Pain: A Prospective, Open-Label Studya,b

BACKGROUND

Gabapentin has been evaluated in the treatment of nonmalignant neuropathic pain, however, there is little direct evidence evaluating its efficacy in cancer-related neuropathic pain.

OBJECTIVE

This study evaluated the effectiveness of gabapentin to treat cancer-related neuropathic pain.

DESIGN

This was an open-label study. Two parallel groups of patients were recruited with either treatment-related (radiotherapy, surgery, chemotherapy) or tumor-related neuropathic pain. Gabapentin was dose-escalated from 300 mg/d to 1.8 g/d.

MEASUREMENTS

The primary outcome, pain, was assessed using the modified brief pain inventory. In addition patient descriptors of pain and scores of activities of daily living were collated together with demographic data.

RESULTS

We recruited 62 patients with treatment-related (n = 25) or tumor-related (n = 37) neuropathic pain. There was a significant reduction in the worst, average, and current pain scores (p < 0.002), but not the least pain score (p = 0.21). Twenty-eight of 62 (45.2%) of patients achieved at least a one third reduction in pain score (95% confidence interval [CI] 32.5-58.3); the number needed to treat to obtain this benefit is 2.2 (95% CI 1.7-3.1). There was a significant reduction in all scores measuring the impact of pain on daily living (p < 0.003). There was no significant difference in pain scores at day 8 compared to day 15. Analysis of variance suggested that gender, but not etiology, or type of neuropathic pain, was a significant predictor of analgesic response and this warrants further investigation.

CONCLUSION

We conclude that gabapentin is an effective treatment for cancer-related neuropathic pain.