Iatrogenic maxillary sinus recirculation and beyond.

Recirculation of nasal mucus occurs when secretions that have been transported out of the natural maxillary ostium return to the sinus via a surgically created or accessory ostium. Recirculation increases the risk of persistent sinus infection. In this article, we describe a case of mucus recirculation in a patient who had not responded to two previous sinus surgeries for recurrent rhinosinusitis.

Services integration and cost-effectiveness.

Alcohol treatment services are increasingly combined with other health and social services to address the needs of multiple-problem clients. Hence, it has been of growing policy interest to find the most effective and the most cost-effective ways of linking these services. This symposium presents some recent studies in this area.

The role of interleukin-8 in the initiation and progression of human cutaneous melanoma.

Background: The expression of Interleukin-8 (IL-8) by human melanoma cells correlates with their metastatic potential in vitro and in nude mice. The role of IL-8 in human patients is not yet clear. The purpose of the present study was to search for a possible correlation between IL-8 in patients' melanoma specimens and the clinical course of the disease.

Subsecond proton-hole propagation in bacteriorhodopsin.

The dynamics of proton transfer between the surface of purple membrane and the aqueous bulk have recently been investigated by the Laser Induced Proton Pulse Method. Following a Delta-function release of protons to the bulk, the system was seen to regain its state of equilibrium within a few hundreds of microseconds. These measurements set the time frame for the relaxation of any state of acid-base disequilibrium between the bacteriorhodopsin's surface and the bulk.

Minimally invasive techniques in the treatment of liver tumors.

Background: Despite advances in cancer therapy the treatment of liver tumors remains a challenge. Most patients are poor candidates for surgical resection; both chemotherapy and irradiation have a low success rate and neither is without complications. New minimally invasive techniques for ablation of unresectable tumors have gained attention as effective treatment alternatives.

A fast in silico simulation of ion flux through the large-pore channel proteins.

The PSST program (see accompanying article) utilizes the detailed structure of a large-pore channel protein as the sole input for selection of trajectories along which negative and positive ions propagate. In the present study we applied this program to reconstruct the ion flux through five large-pore channel proteins (PhoE, OmpF, the WT R. blastica general diffusion porin and two of its mutants).

Gauging of the PhoE channel by a single freely diffusing proton.

In the present study we combined a continuum approximation with a detailed mapping of the electrostatic potential inside an ionic channel to define the most probable trajectory for proton propagation through the channel (propagation along a structure-supported trajectory (PSST)). The conversion of the three-dimensional diffusion space into propagation along a one-dimensional pathway permits reconstruction of an ion motion by a short calculation (a few seconds on a state-of-the-art workstation) rather than a laborious, time-consuming random walk simulations. The experimental system selected for testing the accuracy of this concept was the reversible dissociation of a proton from a single pyranine molecule (8-hydroxypyrene-1,2,3-trisulfonate) bound by electrostatic forces inside the PhoE ionic channel of the Escherichia coli outer membrane.

The sinus node as a nonlinear dynamic system.

The Sinus Node (SN) of the heart is the natural pacemaker driving electrical impulses into the atria, an ordinary excitable medium. In order to avoid wave interference, the SN operation must be of such a nature that no reflections from the atria should occur. It is shown that such a behavior is achieved when the SN operates in a nonlinear dynamical regime situated away from relaxation.

Transureteroureterostomy: an adjunct to the management of advanced primary and recurrent pelvic malignancy.

Background And Aims: The surgical management of advanced primary or recurrent rectal cancer may involve the lower ureter or ureterovesical junction. With unilateral involvement, reconstruction of the ureters with salvage of the ipsilateral renal function should be considered.

Patients And Methods: With optimal exposure both ureters are visualized.

Effect of treatment sequence with radiotherapy and the antiestrogen EM 800 on the growth of ZR 75 1 human mammary carcinoma in nude mice.

We demonstrated previously that continuous administration of EM-800, a SERM having pure antiestrogenic activity in the mammary gland and endometrium in combination with monthly radiotherapy caused a greater inhibition of human ZR 75 1 tumor growth in nude mice than either therapy used alone. To further optimize therapy, we have now examined the effect of various treatment sequences to determine the optimal treatment regimen in the same model. EM 800 was given at the maximally effective oral dose of 300 microg daily.

Aggressive resection of retroperitoneal sarcoma is superior to simple excision: an animal study using a novel model for retroperitoneal sarcoma.

Background And Objectives: Retroperitoneal sarcomas constitute a difficult management problem. The need for, and extent of, aggressive surgery continues to be debated. The aim of our study was to compare the impact of radical en bloc resection of retroperitoneal sarcoma with complete resection of the tumor alone in a rat model.

Proton transfer dynamics on the surface of the late M state of bacteriorhodopsin.

The cytoplasmic surface of the BR (initial) state of bacteriorhodopsin is characterized by a cluster of three carboxylates that function as a proton-collecting antenna. Systematic replacement of most of the surface carboxylates indicated that the cluster is made of D104, E161, and E234 (Checover, S., Y.

Excited state proton transfer in reverse micelles.

The aqueous phase of water/AOT reversed micelles having varying diameters was probed by a single free diffusing proton that was released form a hydrophilic photoacid molecule (2-naphthol-6,8-disulfonate). The fluorescence decay signals were reconstructed through the geminate recombination algorithm, accounting for the reversible nature of the proton-transfer reactions at the surface of the excited molecule and at the water/detergent interface. The radial diffusion of the proton inside the aqueous phase was calculated accounting for both the entropy of dilution and the total electrostatic energy of the ion pair, consisting of the pair-energy and self-energy of the ions.

Stability of an ion channel in lipid bilayers: implicit solvent model calculations with gramicidin.

Gramicidin is a helical peptide, 15 residues in length, which dimerizes to form ion-conducting channels in lipid bilayers. Here we report calculations of its free energy of transfer from the aqueous phase into bilayers of different widths. The electrostatic and nonpolar contributions to the desolvation free energy were calculated using implicit solvent models, in which gramicidin was described in atomic detail and the hydrocarbon region of the membrane was described as a slab of hydrophobic medium embedded in water.

Role of (18)F-FDG dual-head gamma-camera coincidence imaging in recurrent or metastatic colorectal carcinoma.

Unlabelled: (18)F-FDG PET has been shown to be of high diagnostic accuracy for the evaluation of recurrent colorectal cancer. However, the limited availability of PET scanners precludes (18)F-FDG assessment of many patients for whom the study is indicated. An alternative is the SPECT system in coincidence mode.

Kidney allografts and remaining contralateral donor kidneys before and after transplantation: assessment by quantitative (99m)Tc-DMSA SPECT.

Unlabelled: We used (99m)Tc-dimercaptosuccinic acid (DMSA) quantitative SPECT (QDMSA) to assess the function of kidneys before harvesting and after transplantation as well as the function of remaining donor kidneys.

Methods: Nineteen kidney donors underwent a baseline QDMSA study before nephrectomy. The allografts of these kidneys were studied in recipients at 1 wk, 1-2 mo, and 6-15 mo after transplantation.

Comparison of the effects of EM-652 (SCH57068), tamoxifen, toremifene, droloxifene, idoxifene, GW-5638 and raloxifene on the growth of human ZR-75-1 breast tumors in nude mice.

EM-652 exerts pure antiestrogenic activity in the mammary gland and endometrium, while tamoxifen, the antiestrogen most widely used for the treatment of breast cancer, exerts mixed antiestrogenic-estrogenic activity in these tissues. Our objective was to compare the agonistic and antagonistic effects of EM-652 with tamoxifen and 5 other antiestrogens on the growth of ZR-75-1 human breast xenografts in ovariectomized nude mice. During the 23 weeks of treatment at a daily oral dose of 50 microg, EM-652 was the only compound that decreased tumor size relative to pretreatment values, whereas the 6 other antiestrogens only decreased to various extents the progression rate stimulated by estrone.

Proton-collecting properties of bovine heart cytochrome C oxidase: kinetic and electrostatic analysis.

Proton-transfer reactions on the surface of bovine heart cytochrome c oxidase were investigated by combining a laser-induced proton-pulse technique with molecular modeling. The experimental approach simultaneously monitors the state of pyranine protonation in the bulk phase and that of a fluorescein indicator specifically attached to the native Cys(III-115) residue of subunit III of cytochrome oxidase. The reversible dynamics of the acid-base equilibration between the surface and the bulk phase were measured with submicrosecond time resolution and analyzed by numerical integration of coupled nonlinear differential rate equations.

Probing of the substrate binding domain of lactose permease by a proton pulse.

The lactose permease of Escherichia coli coupled proton transfer across the bacterial inner membrane with the uptake of beta-galactosides. In the present study we have used the cysteine-less C148 mutant that was selectively labeled by fluorescein maleimide on the C148 residue, which is an active component of the substrate transporting cavity. Measurements of the protonation dynamics of the bound pH indicator in the time resolved domain allowed us to probe the binding site by a free diffusing proton.

Hydronephrosis associated with colorectal carcinoma: treatment and outcome.

Aim: Obstruction of the upper urinary tract, hydronephrosis, is not uncommon in the context of primary or recurrent colorectal cancer (CRC). Its presence poses a therapeutic dilemma. This study focuses on the significance of hydronephrosis as a prognostic marker for CRC by analysing the resectability and survival rates of patients affected.

Inwards propagating waves in a limit cycle medium.

The existence of a novel inwards propagating wave motion is demonstrated in a limit-cycle medium both for the FitzHugh-Nagumo and for modified Chernyak-Starobin-Cohen reaction-diffusion systems. The waves (pulses) are seen to be moving "backwards," that is, towards the point where the triggering pulse was initiated, instead of the regular propagation away from the origin. The feasibility of the phenomenon and some of its features are analyzed.

Dynamics of the proton transfer reaction on the cytoplasmic surface of bacteriorhodopsin.

The cytoplasmic surface of bacteriorhodopsin is characterized by a group of carboxylates that function as a proton attractive domain [Checover, S., Nachliel, E., Dencher, N.

Multiple primary malignancies in association with soft tissue sarcomas.

Background: Modern cancer treatment has increased the survival of patients with various malignancies substantially. One of the late sequelae of successful treatment is the development of a second malignant tumor. However, in many cases of second primary tumors, exposure to chemotherapy or radiation therapy is not evident, and it should be postulated that the putative mechanism for the development of the second tumor is different.

Time-resolved study of the inner space of lactose permease.

Pyranine (8-hydroxy pyrene-1,3,6-trisulfonate) is a commonly used photoacid that discharges a proton when excited to its first electronic singlet state. Follow-up of its dissociation kinetics reveals the physicochemical properties of its most immediate environment. At vanishing ionic strength the dye adsorbs to the Escherichia coli lactose permease with stoichiometry of 1:1 and an association constant of 2.