[Therapeutic progress in gynecology: organic diseases]

Over the last ten years, progress in evidence-based medicine coupled with technological and surgical breakthroughs have deeply changed the management of our patients. Uterine bleeding is the first cause of gynaecological consultation and the intrauterine progestin delivery system as well as new hysteroscopic procedures have optimized the therapeutic approach to this problem. Introduction of magnetic resonance imaging and interventional procedures have improved breast disease diagnosis and management; likewise sentinel node localization, introduction of aromatase and growth factors inhibitors, new radiotherapy procedures and pharmacogenomics, have helped to ameliorate breast cancer treatment. Pelvic surgery has been switching more and more towards laparoscopic procedures not only in the field of benign lesions (eg endometriosis), of surgery of prolapse and incontinence with new prosthetic materials, but also for an improved management of gynaecological cancers.

Modified pharyngogastrostomy by a stapler technique

Pharyngolaryngoesophagectomy is the gold standard treatment for the majority of larynx, pharynx and cervical esophagus advanced tumours. Reconstruction of these pharyngoesophageal defects is complex, and implicates additional time, morbity and mortality to the procedure. Gastric pull up and pharyngogastrostomy with hand sewing technique is the commonest way of doing it. The authors describe a modified technique to execute it using a stapler device.

The modified Beer-Lambert law revisited

The modified Beer-Lambert law (MBLL) is the basis of continuous-wave near-infrared tissue spectroscopy (cwNIRS). The differential form of MBLL (dMBLL) states that the change in light attenuation is proportional to the changes in the concentrations of tissue chromophores, mainly oxy- and deoxyhaemoglobin. If attenuation changes are measured at two or more wavelengths, concentration changes can be calculated. The dMBLL is based on two assumptions: (1) the absorption of the tissue changes homogeneously, and (2) the scattering loss is constant. It is known that absorption changes are usually inhomogeneous, and therefore dMBLL underestimates the changes in concentrations (partial volume effect) and every calculated value is influenced by the change in the concentration of other chromophores (cross-talk between chromophores). However, the error introduced by the second assumption (cross-talk of scattering changes) has not been assessed previously. An analytically treatable special case (semi-infinite, homogeneous medium, with optical properties of the cerebral cortex) is utilized here to estimate its order of magnitude. We show that the per cent change of the transport scattering coefficient and that of the absorption coefficient have an approximately equal effect on the changes of attenuation, and a 1% increase in scattering increases the estimated concentration changes by about 0.5 microM.

Electroporative Adjustment of pH in Living Yeast Cells: Ratiometric Fluorescence pH Imaging

A number of vital cell functions including modulation of signaling pathways and regulation of the cellular transport critically depends on the cytoplasmic pH. Many pathological cellular changes are related to the abnormal cytosolic pH as well. Reliable and well-calibrated methods for quantification of the cytosolic pH are therefore of high importance. The pH calibration is particularly difficult in walled cells since standard methods fail. In this report we evaluated the new electroporative calibration method of the cytosolic pH in yeasts by the fluorescence microscopy. The calibration was done on living cells using pyranine as a ratiometric pH-sensitive probe. The probe was electroporatively delivered to the cytosol. We have shown that unlike the measurements in suspension the fluorescence microscopy reveals cell subpopulations with different sensitivity to the pH calibration. While the majority of the cells were well calibrated, there was found subpopulation of uncalibrated cell as well as singular cells exhibiting anomalous pH calibration due to the staining of acidic organelles. Resolution of cell subpopulations helps to achieve better pH calibration compared to the calibration in cuvette on a cell suspension.

Pseudo real-time method for monitoring of the limiting anisotropy in membranes

Data acquisition and analysis of the time-resolved fluorescence anisotropy is typically a time consuming process preventing usage of this experimental method for monitoring of time-dependent phenomena. We describe a method for pseudo real-time monitoring of the limiting fluorescence anisotropy r(infinity) allowing to track changes of the membrane order occurring on the time scale of minutes. Principle and performance of the method is demonstrated in the time domain with the time-correlated single photon counting detection. DMPC liposomes stained with 1,6-diphenyl-1,3,5-hexatriene (DPH) have been used to test influence of the diffusion membrane potential on the membrane order during the temperature-induced phase transition in DMPC membranes. It has been found that the transmembrane field of the order of -70 mV increases the phase transition temperature by about 1.5 degrees C-2 degrees C. It is proposed that the full advantage of the method can be utilized with a gated detection, which besides a faster data acquisition brings additional advantage of excitation light suppression. The method can be also used for imaging.

[Duration of induced seizures during selective pharyngeal brain cooling]

Whole body hypothermia can be used to treat the injured brain (e.g. after hypoxic events). Side effects include hemodynamic instability, coagulopathy and infection. Because of these side effects it appears reasonable to cool the brain selectively (selective brain cooling, SBC) without changing the core temperature. A new animal model was used to demonstrate SBC from the pharynx and to examine effects of SBC on the duration of pharmacologically induced seizure activity. Sprague-Dawley rats (n=18, 12 successful experiments) were sedated and mechanically ventilated. Invasive blood pressure monitoring was instituted and blood gases were drawn to evaluate the arterial blood gas status. Electrical brain activity was recorded using a microneedle in the extracellular compartment of the rat brain cortex. Cooled water was circulated through a small tubing into and out of the pharynx of the animals. The cortical as well as the rectal temperature were recorded. After the injection of a single dose of bicuculline (1 mg/kg i.v.) per animal the duration of the induced seizure activity was measured and compared with the temperature prior to the induction of seizure activity. The cortical blood flow (CBF) was detected using intra tissue Doppler signals in the rat cortex in the same location as the EP-study. The influence of a brain temperature reduction between 36.5 degrees to 31.5 degrees C on the seizure duration was examined. There was a positive correlation between the seizure duration and the cortical temperature (r=0.64). Also the CBF was increased during seizure activity (p=0.02) and the increase correlated weakly with cortical temperature (r=0.18). The core temperature remained in the normothermic range (36.9+/-0.7 degrees C) Conclusion: The duration of induced seizures correlates with local brain temperature. In the future further studies should examine the efficiency of induced (selective) brain cooling to treat prolonged seizure activity.

Enhanced sodium absorption in middle ear epithelial cells cultured at air-liquid interface

CONCLUSION

As we demonstrated previously that transcription of alpha-ENaC was correlated with oxygen tension in the culture medium, this study suggests that the increase in alpha-ENaC expression observed under ALI conditions may result from greater oxygenation of ME cells.

OBJECTIVE

The physiology of the middle ear (ME) is primarily concerned with keeping the cavities fluid-free, to allow transmission of sound vibrations from the eardrum to the inner ear. ME epithelial cells are thought to play a key role in this process as they actively absorb sodium and water in order to clear any excess fluid present in the cavities.

MATERIAL AND METHODS

As an air-liquid interface (ALI) model has been shown to improve differentiation and enhance sodium absorption in other respiratory epithelia, we established an ALI model for ME cells.

RESULTS

ME cells cultured under ALI conditions exhibited a fourfold increase in sodium absorption, which was not related to either a metabolic effect or to enhanced morphological differentiation, but instead to an increase in expression of the alpha-subunit of the epithelial sodium channel (alpha-ENaC).

Investigation of the Type-2 Fuzzy Logic Approach to Classification in an EEG-based Brain-Computer Interface

Analysis of electroencephalogram (EEG) requires a framework that facilitates handling the uncertainties associated with the varying brain dynamics and the presence of noise. Recently, the type-2 fuzzy logic systems (T2 FLSs) have been found effective in modeling uncertain data. This paper examines the potential of the T2 FLS methodology in devising an EEG-based brain-computer interface (BCI). In particular, a T2 FLS has been designed to classify imaginary left and right hand movements based on time-frequency information extracted from the EEG with the short time Fourier transform (STFT). Robustness of the method has also been verified in the presence of additive noise. The performance of the classifier is quantified with the classification accuracy (CA). The T2 fuzzy classifier has been proven to outperform its type-1 (T1) counterpart on all data sets recorded from three subjects examined. It has also compared favorably to the well known classifier based on linear discriminant analysis (LDA).

Identifying and characterizing a novel activating mutation of the FLT3 tyrosine kinase in AML

The FLT3 receptor is activated by juxtamembrane insertion mutations and by activation loop point mutations in patients with acute myeloid leukemia (AML). In a systematic tyrosine kinase gene exon resequencing study, 21 of 24 FLT3 exons were sequenced in samples from 53 patients with AML, 9 patients with acute lymphoblastic leukemia (ALL), and 3 patients with myelodysplasia samples. Three patients had novel point mutations at residue N841 that resulted in a change to isoleucine in 2 samples and to tyrosine in 1 sample. Introduction of FLT3-N841I cDNA into Ba/F3 cells led to interleukin-3 (IL-3)–independent proliferation, receptor phosphorylation, and constitutive activation of signal transducer and activator of transcription 5 (STAT5) and extracellular regulatory kinase (ERK), suggesting that the N841I mutation confers constitutive activity to the receptor. An FLT3 inhibitor (PKC412) inhibited the growth of Ba/F3-FLT3N841I cells (IC50 10 nM), but not of wild-type Ba/F3 cells cultured with IL-3. PKC412 also reduced tyrosine phosphorylation of the mutant receptor and inhibited STAT5 phosphorylation. Examination of the FLT3 autoinhibited structure showed that N841 is the key residue in a hydrogen-bonding network that likely stabilizes the activation loop. These results suggest that mutations at N841 represent a significant new activating mutation in patients with AML and that patients with such mutations may respond to small-molecule FLT3 inhibitors such as PKC412.

A simple technique for removal of the gallbladder during microlaparoscopic cholecystectomy

With the advent of mini-instruments, laparoscopic cholecystectomies have been performed with two or three trocars instead of the standard four ports. However, removal of the gallbladder is a difficult aspect with these microlaparoscopic techniques. To remove the gallbladder through the 11-mm umbilical port, a 5-mm telescope should be used. However this telescope is not always available. Other techniques are suitable only for patients with limited or no inflammation of the gallbladder. An efficient, simple, and inexpensive technique is described that allows removal of the gallbladder through an 11-mm trocar without the need for a 5-mm telescope. It permits removal of the specimen in acute suppurative or thick-wall cholecystitis independently of the technique used.

EGFR mutations in lung cancer: correlation with clinical response to gefitinib therapy

Receptor tyrosine kinase genes were sequenced in non-small cell lung cancer (NSCLC) and matched normal tissue. Somatic mutations of the epidermal growth factor receptor gene EGFR were found in 15of 58 unselected tumors from Japan and 1 of 61 from the United States. Treatment with the EGFR kinase inhibitor gefitinib (Iressa) causes tumor regression in some patients with NSCLC, more frequently in Japan. EGFR mutations were found in additional lung cancer samples from U.S. patients who responded to gefitinib therapy and in a lung adenocarcinoma cell line that was hypersensitive to growth inhibition by gefitinib, but not in gefitinib-insensitive tumors or cell lines. These results suggest that EGFR mutations may predict sensitivity to gefitinib.