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.

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.

Genome coverage and sequence fidelity of phi29 polymerase-based multiple strand displacement whole genome amplification

Major efforts are underway to systematically define the somatic and germline genetic variations causally associated with disease. Genome-wide genetic analysis of actual clinical samples is, however, limited by the paucity of genomic DNA available. Here we have tested the fidelity and genome representation of phi29 polymerase-based genome amplification (phi29MDA) using direct sequencing and high density oligonucleotide arrays probing >10,000 SNP alleles. Genome representation was comprehensive and estimated to be 99.82% complete, although six regions encompassing a maximum of 5.62 Mb failed to amplify. There was no degradation in the accuracy of SNP genotyping and, in direct sequencing experiments sampling 500,000 bp, the estimated error rate (9.5 x 10(-6)) was the same as in paired unamplified samples. The detection of cancer-associated loss of heterozygosity and copy number changes, including homozygous deletion and gene amplification, were similarly robust. These results suggest that phi29MDA yields high fidelity, near-complete genome representation suitable for high resolution genetic analysis.

[Benefits and limitations of mammography]

The literature on screening mammography provides ample opportunity for doubt (the sceptics) and dogma (the screening zealots), and can be interpreted to prove both benefit and harm. The benefit of mammography screening, if any, is modest and the balance between beneficial (potentially, a 20% relative reduction in breast cancer mortality with no significant benefit on all-cause mortality) and harmful (physical and psychological morbidity related to the 15-40% missed cancers and the 80-90% false-positive diagnoses) effects is still delicate. The mammogram alone is a modest weapon. Concurrent clinical breast examination is mandatory. Women that are concerned about breast cancer should be fully informed of the potential benefits and risks of screening mammography. These women should benefit from mammography with concurrent clinical breast examination, and possible whole-breast ultrasound in heterogeneously dense and extremely dense breast patterns.

Breast cancer and serum organochlorine residues

BACKGROUND

Controversy still exists about the breast carcinogenic properties in humans of environmental xenoestrogens (organochlorines), justifying new investigations.

AIMS

To compare the blood levels of total dichlorodiphenyltrichloroethane (DDT) and hexachlorobenzene (HCB) in samples collected at the time of breast cancer discovery, in order to avoid the potential consequences of body weight change (after chemotherapy or radiotherapy) on the pesticide residue levels.

METHODS

Blood levels of HCB and total DDT (we calculated total DDT concentrations by adding all DDT and DDE isomers) were compared in 159 women with breast cancer and 250 presumably healthy controls. Risk of breast cancer associated with organochlorine concentration was evaluated.

RESULTS

Mean levels of total DDT and HCB were significantly higher for breast cancer patients than for controls. No differences in serum levels of total DDT or HCB were found between oestrogen receptor positive and oestrogen receptor negative patients with breast cancer.

CONCLUSIONS

These results add to the growing evidence that certain persistent pollutants may occur in higher concentrations in blood samples from breast cancer patients than controls.

[Endoscopic resection of the frontal sinus floor following the Draf procedure: long term results and therapeutic algorithm]

OBJECTIVES

Endoscopic resection of the frontal sinus floor is a minimally invasive and functional surgical procedure designed for the treatment of inflammatory sinus diseases, which avoids the side-effects of external osteoplastic obliteration. The aim of the study was to evaluate long term results and to determine computed tomographic criteria predictive of success.

PATIENTS AND METHODS

Our study reports the results of 20 patients operated for nasofrontal stenosis associated or not with osteitis or secondary mucocele.

RESULTS

A successful result was obtained in 90% with a mean follow-up of 3.5 years. Failures (2) were attributed to insufficient resection and to frontal sinus osteogenesis.

CONCLUSION

Endoscopic frontal sinusotomy is a safe and effective procedure for large sinuses with large distance between nasion and cribriform plate, but not in case of osteogenesis and multiple mucoceles. In case of unfavourable anatomy, or for the aforementioned pathologies, the obliteration procedure should be preferred.

Selektive pharyngeale Hirnkühlung. Selective Brain Cooling from the Pharynx

Whole-body cooling can be used in the treatment of various brain pathologies, for example, after hypoxic events. Potential complications include haemodynamic instability, coagulation disorders and infection. Selective brain cooling (SBC) would therefore appear to make good sense. In an animal model a new approach to SBC was therefore evaluated. A rat weighing 350 g was sedated with alpha-chloralose (40 mg/kg/h) and d-tubocurarine (4.05 mg/kg/h), mechanically ventilated and placed on a heating pad. A thermocouple was introduced into the somatosensory cortex to a depth of 2.5 mm. SBC was achieved using a novel approach: PTFE tubing (ID 100 microns) with an inlet and an outlet was wrapped around and glued to a piece of wood, and introduced non traumatically into the pharynx. The tubing was perfused with cold water (+4 degrees C). Under SBC the cortical temperature dropped from 38.4 degrees C to 27.7 degrees C while the core temperature remained stable. In an animal model SBC was successfully accomplished via the pharynx. Further studies should now be done to evaluate the effectiveness of this approach in larger animals with potentially different anatomical features.

Fractal characterization of complexity in temporal physiological signals

This review first gives an overview on the concept of fractal geometry with definitions and explanations of the most fundamental properties of fractal structures and processes like self-similarity, power law scaling relationship, scale invariance, scaling range and fractal dimensions. Having laid down the grounds of the basics in terminology and mathematical formalism, the authors systematically introduce the concept and methods of monofractal time series analysis. They argue that fractal time series analysis cannot be done in a conscious, reliable manner without having a model capable of capturing the essential features of physiological signals with regard to their fractal analysis. They advocate the use of a simple, yet adequate, dichotomous model of fractional Gaussian noise (fGn) and fractional Brownian motion (fBm). They demonstrate the importance of incorporating a step of signal classification according to the fGn/fBm model prior to fractal analysis by showing that missing out on signal class can result in completely meaningless fractal estimates. Limitation and precision of various fractal tools are thoroughly described and discussed using results of numerical experiments on ideal monofractal signals. Steps of a reliable fractal analysis are explained. Finally, the main applications of fractal time series analysis in biomedical research are reviewed and critically evaluated.

[Is sudden sensorineural hearing loss a therapeutic emergency? Early results in a prospective cohort of 136 patients]

Idiopathic sudden sensorineural hearing loss is one of the most controversial issues in otology. A prospective cohort study including 136 sudden hearing losses seen at the ENT emergency referral center of Lariboisiere Hospital during an 18-month period was conducted. Patients were hospitalized and a corticotherapy course was administered, eventually associated with an antiviral treatment, low molecular weight dextran or sedative. At the end of the 5-day hospitalization, 74% of the patients had recovered, at least partially, with a mean gain of 22 dB. The outcome was considered satisfactory, i.e. superior to 50% of the initial loss, in 30% of the patients. After 1 month, 86% of the patients recovered at least partially with a mean gain of 30 dB. The outcome was considered satisfactory in 44% of the patients. A prognosis analysis showed that vertigo, age of the patient and anacusis are pejorative factors. Ascending audiogram shapes seem to involve a better prognosis. The therapeutic delay is not correlated with the quality of the outcome, which questions the classical notion of therapeutic emergency.

Texture analysis of fluorescence lifetime images of AT- and GC-rich regions in nuclei

We used intensity and fluorescence lifetime microscopy (FLIM) of 3T3 nuclei to investigate the existence of AT-rich and GC-rich regions of the nuclear DNA. Hoechst 33258 (Ho) and 7-aminoactinomycin D (7-AAD) were used as fluorescence probes specific for AT and GC base pairs, respectively. YOYO-1 (Yo) was used as a dye that displays distinct fluorescence lifetimes when bound to AT or GC base pairs. We combined fluorescence imaging of Ho and 7-AAD with time-resolved measurements of Yo and took advantage of an additional information content of the time-resolved fluorescence. Because a single nucleus could not be stained and measured with all three dyes, we used texture analysis to compare the spatial distribution of AT-rich and GC-rich DNA in 100 nuclei in different phases of the cell cycle. The fluorescence intensity-based analysis of Ho- or 7-AAD-stained images indicates increased number and larger size of the DNA condensation centers in the G2/M-phases compared to G0/1-phases. The lifetime-based study of Yo-stained images suggests spatial separation of the AT- or GC-rich DNA regions in the G2/M-phase. Texture analysis of fluorescence intensity and lifetime images was used to quantitatively study the spatial change of condensation and separation of AT- and GC-rich DNA during the cell cycle.

Pancreatic head tumors with portal vein involvement: an alternative surgical approach

BACKGROUND/AIMS

One of the determining factors for the unresectability of pancreatic head tumors is the involvement of the portal venous system. Recent reports show that the resection of tumors with portal vein involvement has similar results to lesions with same stage without portal vein invasion. The aim of this study is to present a technique that allows the resection of portal vein segments without the use of grafts and with a shorter period of intraoperative venous occlusion.

METHODOLOGY

Fifteen patients with pancreatic head tumors and portal vein involvement were submitted to pancreaticoduodenectomy according to this technique. The main feature of the technique is starting the pancreatic dissection at the posterior aspect of the head of the pancreas. The superior mesenteric artery is completely dissected from the pancreatic tissues leaving the section of the pancreas and the resection of the portal vein to the last step.

RESULTS

Portal vein flow occlusion did not exceed 10 minutes. There were no major postoperative complications or mortality.

CONCLUSIONS

This maneuver allows an easier resection of the mobilized portal vein with a shorter period of venous clamping and reconstruction without the need of venous graft.

[Epidemiology and clinical findings in 20,563 patients attending the Lariboisière Hospital ENT Adult Emergency Clinic]

OBJECTIVES

Study the epidemiological and clinical features of patients attending the Lariboisière Hospital (Paris) ENT adult emergency clinic (La Grande Garde) over the first 18 months of operation (November 2, 1998 to May 5, 2000) in order to ascertain practical implications for organization, hospitalization and teaching.

MATERIAL AND METHODS

20.563 adult patients attended the ENT emergency clinic. Among them 1.225 were hospitalized after emergency care. Parameters analyzed were: age, sex, mode of referral to the clinic, hour and day of arrival, geographical origin, waiting time, initial signs and pathological situations encountered.

RESULTS

The most frequently observed symptoms leading to the emergency room consultation were: pain, sudden loss of hearing, bleeding, a swallowed foreign body. The most frequent nasal sign was epistaxis, the most frequent auditory condition was acute external and middle ear otitis, and the most frequent pharyngeal condition was ingestion of a foreign body. Among the 1.225 patients who were hospitalized, the most frequent conditions were epistaxis, peritonsilar phlegmon, sudden hearing loss and swallowed foreign body. Major life-threatening emergencies requiring immediate transfer to the operating room and surgery accounted for 0.5% of the patients, i.e. one "vital" emergency every 5 days.

CONCLUSIONS

Emergency ENT care for adults is an important sector of hospital activity with a mean 38 consultations per day. However, only 10% of the consultation in the emergency unit appear to be real medical emergencies. Care for many of these patients could be appropriately provided by a general practitioner, pointing out the importance of education concerning ENT disorders. There was a homogeneous distribution between men and women for the different disease conditions, except for foreign bodies which occurred more frequently in women and epistaxis and facial trauma where men predominated. Life-threatening emergencies accounted for 0.5% of all cases, i.e. one case every 5 days.

Frequency-domain fluorescence microscopy with the LED as a light source

We describe a frequency-domain lifetime fluorometer based on a microscope and a modulated light-emitting diode (LED) excitation source (370/460 nm), which operates in the frequency range 120 Hz--250 MHz. We collected multifrequency phase and modulation fluorescence responses from cellular areas as small as 10--15 microm in diameter. We also collected fluorescence lifetime data from cells stained by a lipophilic coumarin sensitized europium fluorophore, Coum-Eu, with a millisecond lifetime, and Ru(bpy)(2)phe-C(12),with microsecond lifetime. Nanosecond lifetimes from native nuclei stained with SYTO 14 and SYTO 16 probes were measured as well. We demonstrate that a simple LED excitation source can, for many applications, successfully replace complex and expensive laser systems, which have been used for cellular frequency-domain lifetime measurements. As the LEDs are very stable with low noise, it will be possible to image even smaller sample areas using brighter LEDs. With availability of modulated LEDs emitting at several wavelengths covering almost the entire visible spectrum it is easy to assemble a system for the fluorophore of choice. The ability to select an excitation source for a given fluorophore and low price make such an excitation source even more practical.

Fluorescence lifetime characterization of novel low-pH probes

The structures and functions of the cellular acidic compartments are strongly dependent on the pH gradients across vesicular membranes. Measurement and imaging of the vesicular pH require fluorophores with appropriate pK(a) values. In this report, we characterized the pH-dependent lifetime responses of a family of acidotropic probes, LysoSensors, to evaluate their usefulness to low-pH lifetime imaging. LysoSensors are cell-permeable weak bases that selectively accumulate in acidic vesicles after being protonated. They have higher quantum yields at lower pH ranges to allow visualization of the lysosomes. For LysoSensors DND-167, DND-189, and DND-153, raising the buffer pH increased the quenching effects of their basic side chains and substantially reduced their steady-state fluorescence and lifetimes. The apparent pK(a) values determined from their lifetime responses were shifted to near neutral values because of the dominant intensity contribution from their protonated species. One unique property of LysoSensor DND-189 is its nonmonotonic lifetime responses of the maxima occurring between pH 4 and 5. LysoSensor DND-192 did not show significant lifetime changes over a wide pH range. LysoSensor DND-160, which was the only excitation and emission ratiometric probe, showed significant pH-dependent lifetime changes as well as its spectral shifts. Its apparent pK(a) values determined from the lifetime responses were comparable to the lysosomal pH because of its bright basic form. Because of the pH-dependent absorption spectra, the apparent pK(a) values could be manipulated between 3 and 5 by changing the excitation and/or emission wavelengths. These results indicate that LysoSensor DND-160 is a promising probe for lifetime imaging to determine lysosomal pH.

Fluorescence properties of albumin blue 633 and 670 in plasma and whole blood

We have determined the fluorescence characteristics of two long wavelength dyes, albumin blue 633 (AB633) and 670 (AB670), in plasma and blood to evaluate the possibility of making direct fluorescence sensing measurements in blood. Using binding and lifetime measurements we were also able to show that these dyes bind selectively to human serum albumin (HSA) in plasma and blood. By measuring changes in the mean lifetime of AB670 with changes in the HSA concentration, we showed that lifetime-based sensing can be used to monitor HSA concentrations using these albumin blue dyes. Anisotropy measurements for AB633 and AB670 in plasma and blood revealed high anisotropy values for these dyes in these media. Exploiting these high anisotropies, we were also able to determine HSA concentrations in plasma and blood mimics using changes in AB670 anisotropy with HSA concentration. These results show that, apart from being able to make fluorescence measurements directly in plasma and blood, it is possible to sense directly for specific plasma/blood components using fluorescent probes that bind preferentially to them.

Insulinoma: diagnostic strategies and surgical treatment. A 22-year experience

BACKGROUND/AIMS

The efficacy of preoperative localization methods and the results of the surgical treatment of insulinoma were studied.

METHODOLOGY

Fifty-nine patients referred for surgical treatment were studied and the results of the diagnostic tools for tumor localization were compared with findings at surgical intervention. The influence of the type of surgical procedure in the immediate and late postoperative course was also studied.

RESULTS

Ultrasonography had a sensitivity of 30%, computed tomography 25%, angiography 54%, portal vein sampling 94%, endoscopic ultrasonography 27% and magnetic resonance 17%. Intraoperative palpation localized 98.2% of the tumors and by the addition of intraoperative echography, all lesions were identified. In 55 patients with benign lesions, 22 enucleations, 25 distal pancreatectomies, 7 pancreatectomies plus enucleation and one duodenopancreatectomy were performed. Malignant tumors were treated by pancreatic resection, postoperative hepatic artery embolization and systemic chemotherapy. There was no postoperative mortality. Pancreatic fistula was the most common complication. Three patients who underwent distal pancreatectomy developed late diabetes (9.3%).

CONCLUSIONS

Extensive preoperative investigation, mainly with invasive methods, is not indicated and by combining intraoperative palpation and echography most of the cases can be adequately dealt with. Preservation of pancreatic tissue with enucleation and preservation of the spleen are the best choice for treatment of benign insulinomas.

Production of nitric oxide by the middle ear epithelium and subsequent inhibition of sodium transport

The production of nitric oxide (NO) within the middle ear has not previously been characterized. The presence of NO synthase (NOS) transcripts was demonstrated using RNA amplification by reverse transcriptase-polymerase chain reaction in rat middle ear mucosa and in rat primary cultured middle ear epithelial cells. The expression of NOS was indirectly assessed by nitrite measurement in the supernatant of primary cultured cells. The effect of NO on ion transport was investigated in a previously described middle ear epithelial cell line using the short-circuit current (Isc) technique. NO per se had no effect on Isc. However, previous work has shown that sodium transport is stimulated by reactive oxygen species (ROS). NO blunted this stimulation, an inhibition probably related to the toxicity of peroxynitrite, ONOO-, a highly reactive compound. These results suggest that NO is produced by middle ear epithelial cells and that, in the presence of ROS, NO may be responsible for an inhibition of ion transport viaperoxynitrite formation.

Aneurysmal bone cyst in the sphenoid bone: treatment with minimally invasive surgery

Aneurysmal bone cysts are vascular lesions that destroy and expand bone. We report a recently treated case of an aneurysmal cyst of the sphenoid bone. A 14-year-old girl presented with frontal headaches, bouts of nausea, and vomiting. Computed tomography and magnetic resonance imaging showed typical features of an aneurysmal bone cyst. Arterial embolization was undertaken before surgery. The endoscopic transnasal procedure used allowed the complete removal of the aneurysmal bone cyst. This use of minimally invasive surgery makes this case of interest to surgeons of the skull base and sinuses.

Serous or mucoid effusion in the course of secretory otitis media: influence of ion transport modulation

OBJECTIVE

Secretory otitis media is defined by a chronic effusion in the middle ear cavities, behind an intact tympanic membrane without acute infection. In the course of secretory otitis media, the effusion is sometimes thick (or mucoid) and other times thin (or serous). For several authors, these differences might be related to different inflammatory levels rather than to distinct pathophysiological mechanisms. The purpose of this study was to determine whether the modulation of ion transport by inflammation could account for the differences observed in the aspect of ME effusion.

METHODS

Hydrogen peroxide (H2O2), used as an inflammation model was tested on a middle ear cell line (MESV) in culture.

RESULTS

Results show that low and high concentrations of H2O2 have opposite effects on ion (and then water) absorption by the middle ear epithelium.

CONCLUSION

the modulation of ion and water absorption by inflammation could modify the mucins concentration in the effusion, and explain observed viscosity differences in the course of secretory otitis media.

Expression of NMDA, AMPA and GABA(A) receptor subunit mRNAs in the rat auditory brainstem. I. Influence of early auditory deprivation

Impact of early post-natal deafening on auditory pathways was investigated in newborn rats deafened by daily amikacin injections from P7 to P16 inducing a complete destruction of the organ of Corti. The expression of mRNAs encoding N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazole (AMPA) and gamma-aminobutyric acid type A (GABA(A)) receptor subunits was then studied by in situ hybridization in the dorsal and ventral cochlear nucleus and in the central nucleus of the inferior colliculus (CNIC). Early post-natal deafening decreased bilaterally the expression of mRNAs encoding NR1, NR2a, NR2b and flop isoforms of AMPA receptors. On the contrary, it increased the expression of mRNAs encoding some GABA(A) subunits (alpha1, beta1, gamma2) and flip isoforms of AMPA receptors. These changes were more pronounced in cochlear nuclei than in CNIC. They suggest that auditory sensation is essential in the normal development of central auditory pathways.

Expression of NMDA, AMPA and GABA(A) receptor subunit mRNAs in the rat auditory brainstem. II. Influence of intracochlear electrical stimulation

We investigated the effects of intracochlear electrical stimulation (ICES) on auditory pathways of neonatal rat deafened by daily amikacin injections. Expression of mRNAs encoding ionotropic glutamate receptor subunits such as alpha-amino-3-hydroxy-5-methyl-4-isoxazole (AMPA) and N-methyl-D-aspartate (NMDA), and gamma-aminobutyric acid type A (GABA(A)) receptor subunits was assessed by in situ hybridization in the dorsal (DCN) and the ventral cochlear nucleus (VCN) and in the central nucleus of the inferior colliculus (CNIC). After 15 days of daily unilateral ICES, the expressions of NR1, NR2b and NR2c subunits of NMDA receptor, that of GluRA, B, C, D flop isoforms of AMPA receptor and that of some GABA(A) subunits (alpha1, beta1, gamma1, gamma2) were increased bilaterally in the DCN, VCN and the CNIC. These changes last over a week after stimulation for only NR1 and NR2c. These modifications might be related to long lasting synaptic plasticity of brainstem auditory pathways. As far as analogy to deaf children can be made, early electrical stimulation might be of interest to maintain neuronal networks.

A new technique of gastroenterostomy for palliative treatment of pancreatic head carcinoma

BACKGROUND/AIMS

Most of the patients with pancreatic cancer can be only palliatively treated. Although 30% of the patients submitted to palliative biliary bypass will require further treatment for duodenal obstruction, prophylactic gastric bypass still remains a controversial issue in the management of unresectable pancreatic head carcinoma. The main disadvantage of current techniques of gastrojejunostomy is postoperative vomiting due to impaired gastric motility and circulus vitiosus through the nonobstructed duodenum. A new technique of prophylactic gastrojejunostomy is described herein as an attempt to obviate these complications.

METHODOLOGY

An antecolic isoperistaltic gastrojejunostomy was fashioned at the gastric mid-body above the angulus. The afferent limb was partitioned close to the gastrojejunostomy and a Braun type entero-enterostomy constructed joining the afferent and the efferent limbs. Following the gastrojejunostomy a Roux-en-Y choledochojejunostomy was performed.

RESULTS

In 19 patients consecutively submitted to this procedure no postoperative mortality or complications occurred. Nasogastric suction was interrupted at postoperative day 3 and oral feeding resumed on the next day. Neither early nor late postoperative vomiting was observed.

CONCLUSIONS

These encouraging preliminary results suggest that this procedure may have its place in the palliative treatment of pancreatic head carcinoma.