Local RF capacitive hyperthermia: thermal profiles and tumour response

At the Cancer Institute we are using RF capacitive hyperthermia as an adjuvant to radiotherapy and/or chemotherapy in the local control of soft tissue sarcomas. We have studied the influence of bolus conductivity, electrode and phantom sizes on the rate of heating of agar phantoms. We have varied the bolus conductivity by varying the saline concentration in the bolus bags from zero to 2.0 per cent, during heating. We found that the rate of heating of phantoms increases and that of the bolus decreases with the increase in the saline concentration of bolus up to 1 per cent, irrespective of phantom and electrode sizes. However, for a given size of electrodes the rate of heating decreased with the increase in the phantom size. When the diameter and height of the phantom were equal to the diameters of electrodes the rate of heating of the phantom was nearly uniform. However, when the diameter of the phantom was larger than that of electrodes the rate of heating in the radial axis decreased with the increase in the radial distance. On the basis of this data we suggest the use of electrodes larger in size by 1.0-3.0 cm than the size of the tumour, where the size of the anatomical site to be heated is larger than the electrode size to be used. Phantom and clinical data have indicated that the presence of bone in the field of heating can lead to hot spots. Preliminary clinical results have shown that the response of sarcomas to thermo-chemo-radiotherapy was superior to that of either thermo-radiotherapy or radiotherapy alone.     

Novel KIR genotypes and gene copy number variations in northeastern Thais

KIR (Killer Immunoglobulin‐like Receptor) variants influence immune responses and are genetic factors in disease susceptibility. Using sequence‐specific priming PCR, we have previously described the diversity of KIR genes in term of presence/absence in northeastern Thais (NETs). To provide additional resolution beyond conventional methods, quantitative PCR was applied to determine KIR copy number profiles. Novel expanded and contracted KIR copy number profiles were identified at cumulatively high frequencies. These all comprise haplotypes with duplication (6·9%) or deletion (2·7%) of KIR3DL1/S1 along with adjacent genes. Five expanded KIR profiles comprised haplotypes with duplications of KIR2DP1, 2DL1, 3DP1, 2DL4, 3DL1/S1 and 2DS1/4, whereas two contracted profiles contained only a single copy of KIR3DP1, 3DL1/S1 and 2DL4. Using a KIR haplotype prediction program (KIR Haplotype Identifier), 14% of NET haplotypes carried atypical haplotypes based on the gene copy number data.     

Histone deacetylase inhibitors and candidate gene expression: An in vivo and in vitro approach to studying chromatin remodeling in a clinical population

Objective

The emerging field of psychiatric epigenetics is constrained by the dearth of research methods feasible in living patients. With this focus, we report on two separate approaches, one in vitro and one in vivo, developed in our laboratory.

Method

In the first approach, we isolated lymphocytes from 12 subjects and cultured their cells with either 0.7 mM valproic acid (VPA), 100 nM Trichostatin A (TSA), or DMSO (control) for 24 h based upon previous dose response experiments. We then measured GAD67 mRNA expression using realtime RT-PCR, total acetylated histone 3 (H3K9,K14ac) levels using Western blot analysis, and attachment of H3K9,K14ac to the GAD67 promoter using ChIP. In the second approach, we measured GAD67 mRNA and total H3K9,K14ac levels in lymphocytes from 11 schizophrenia and 7 bipolar patients before and after 4 weeks of clinical treatment with Depakote ER^® (VPA).

Results

In the first approach, VPA induced a 383% increase in GAD67 mRNA, an 89% increase in total H3K9,K14ac levels, and a 482% increase in H3K9,K14ac attachment to the GAD67 promoter. TSA induced comparable changes on all measures. In the second approach, bipolar subjects had significantly higher baseline levels of H3K9,K14ac compared to subjects with schizophrenia. Subjects with clinically relevant serum levels of VPA (?65 μg/mL) showed a significant increase in GAD67 mRNA expression.

Conclusions

Our results utilizing two separate approaches for examining chromatin remodeling in real clinical time provide possible means to investigate epigenetic events in living patients.     

Treatment of traumatic cervical arteriovenous fistulas with N-butyl-2-cyanoacrylate

We report 2 cases of traumatic arteriovenous fistulas in the neck treated with transarterial embolization with n-butyl-2-cyanoacrylate (n-BCA). In both cases, covered stent placement across the fistula to preserve the artery was not possible. Detachable coil placement was attempted in one case but was not successful. Both fistulas were successfully treated with n-BCA embolization. To our knowledge, these are the first 2 such cases reported of high-flow cervical arteriovenous fistulas treated with n-BCA embolization.     

α7 and non-α7 nicotinic acetylcholine receptors modulate dopamine release in vitro and in vivo in the rat prefrontal cortex

Nicotine enhances attentional and working memory aspects of executive function in the prefrontal cortex (PFC) where dopamine plays a major role. Here, we have determined the nicotinic acetylcholine receptor (nAChR) subtypes that can modulate dopamine release in rat PFC using subtype-selective drugs. Nicotine and 5-Iodo-A-85380 (β2* selective) elicited [³H]dopamine release from both PFC and striatal prisms in vitro and dopamine overflow from medial PFC in vivo . Blockade by dihydro-β-erythroidine supports the participation of β2* nAChRs. However, insensitivity of nicotine-evoked [³H]dopamine release to α-conotoxin-MII in PFC prisms suggests no involvement of α6β2* nAChRs, in contrast to the striatum, and this distinction is supported by immunoprecipitation of nAChR subunits from these tissues. The α7 nAChR-selective agonists choline and Compound A also promoted dopamine release from PFC in vitro and in vivo , and their effects were enhanced by the α7 nAChR-selective allosteric potentiator PNU-120596 and blocked by specific antagonists. DNQX and MK801 inhibited [³H]dopamine release evoked by choline and PNU-120596, suggesting crosstalk between α7 nAChRs, glutamate and dopamine in the PFC. In vivo, systemic (but not local) administration of PNU-120596, in the absence of agonist, facilitated dopamine overflow in the medial PFC, consistent with the activation of extracortical α7 nAChRs by endogenous acetylcholine or choline. These data establish that both β2* and α7 nAChRs can modulate dopamine release in the PFC in vitro and in vivo . Through their distinct actions on dopamine release, these nAChR subtypes could contribute to executive function, making them specific therapeutic targets for conditions such as schizophrenia and attention deficit hyperactivity disorder.     

Synthesis, spectral, theoretical, and antimicrobial screening of some heterocyclic oximes

In a wide research program toward new and efficient antimicrobial agents, a series of substituted N-nitroso-3-alkyl piperidone oximes were synthesized and their antibacterial activity against Staphylococcus aureus, Pseudomonas aerugonisa, Escherichia coli, and Klbesiella pneumoniae and antifungal activity against Aspergillus niger, Aspergillus flavus, and Rhizopus were evaluated. Their structure and stereochemistry were characterized by high-resolution ¹H NMR, mass and elemental analysis. The spectra of all N-nitroso oximes reveal the presence of two isomers labeled as E (–NOH group is anti to N–N=O moiety) and Z (–NOH group is syn to N–N=O moiety) in solution and the coupling constants ruled out the possibility of normal chair conformation. From the theoretical studies and coupling constant values, it was found that all N-nitroso oximes exist as an equilibrium mixture of CA boat conformation (B ₁) and the major isomer was found to be E isomer. The molecular structure of N-nitroso oximes were also determined by semiempirical and Gaussian-03 calculation and the results are in agreement with the experimental studies.