Liquid-liquid extraction of selenium (IV) ions from hydrochloric acid solution using Aliquat 336 dissolved in kerosene.

Solvent extraction of selenium(IV) ions from highly concentrated hydrochloric acid using 0.4 mol/L Aliquat 336 dissolved in kerosene was investigated. As a modifying agent, 1-octanol (10% v/v) was added to the organic phase to avoid the third phase formation. The effect of different parameters affecting the liquid-liquid extraction of selenium(IV) such as the acid concentration, shaking time, metal ion concentration in the aqueous phase, loading capacity, diluents, and temperature, was studied. The results indicate that selenium(IV) is extracted efficiently by 0.4 mol/L Aliquat 336 dissolved in kerosene. It was noticed that the extraction increased with the increase in the acid and Aliquat 336 concentrations, reaching an extraction percentage of about 92% at 8 mol/L HCl and 97.1% at 1 mol/L extractant. The extracted organic species is postulated to be [H2SeO2Cl2.2R4NCl]org by using the slope analysis method, and the value of Kex for selenium(IV) extraction was found to be 26.17 ± 2 M- 2. The structure of the extracted organic species was confirmed by FT-IR. The effect of diluents using various aliphatic and aromatic diluents indicated that kerosene is the most preferred diluent. This is owing to safety ground purpose, economic consideration, the lower cost, availability, and lower toxicity. Thermodynamic parameters indicate the endothermic nature for the solvent extraction of selenium(IV) for the investigated system according to the positive value obtained of the enthalpy change (ΔH). Depending on the obtained results, the method was used to recover selenium(IV) from a simulated solution synthesized in hydrochloric acid medium, which is expected in anode slime leach liquor solution.

Microwave-ultrasonic assisted extraction of lignin to synthesize new nano micellar organometallic surfactants for refining oily wastewater.

In this work, a beneficial approach for efficient depolymerization of lignin and controllable product distribution is provided. Lignin, an abundant aromatic biopolymer, has the potential to produce various biofuels and chemical adsorption agents and is expected to benefit the future circular economy. Microwave-ultrasonic (MW/US) assisted efficient depolymerization of lignin affords some aromatic materials used in manufacturing the starting material to be investigated. Some nano organometallic surfactants (NOMS) based on Ni2+, Cu2+, Co2+, Fe3+, and Mn2+ besides 2-hydroxynaphth-sulphanilamide are synthesized to enhance oil recovery (EOR). In this work, the assessment of the NOMS's efficiency was improving the heavy oil recovery via the study of the dynamic interfacial tension (IFT), contact angle, and chemical flooding scenarios. The NOMS-Ni2+ exhibited the maximum reduction of viscosity and yield values. Dropping the viscosity to 819.9, 659.89, and 499.9 Pa s from blank crude oil viscosity of 9978.8, 8005.6, and 5008.6 Pa s respectively at temperatures of 40, 60, and 80 °C was investigated. The reduction of τB values was obtained also by OMS-Ni2+. The minimum IFT was recorded against the Ni2+ derivatives (0.1 × 10-1 mN m-1). The complete wettability alteration was achieved with the NOMS-Ni2+ surfactant (ɵ ≅ 6.01 ) . The flooding test has been steered in 3 sets using the sand-packed model as a porous media at surfactant concentrations (1, 1.5, 2 and 2.5%) at 50 °C and 499 psi as injection pressure. The best value (ORs) formed for NOMS-Ni2+ were 62, 81, 85.2, and 89% respectively as compared with other NOMS-M2+ at the same concentrations. The mechanism of alternating wettability was described in the text. The rheology of the used heavy crude oil was investigated under temperatures of 40, 60, and 80 °C.

Modeling and equilibrium studies on the recovery of praseodymium (III), dysprosium (III) and yttrium (III) using acidic cation exchange resin.

In this research, the possibility of using hydrogenated Dowex 50WX8 resin for the recovery and separation of Pr(III), Dy(III) and Y(III) from aqueous nitrate solutions were carried out. Dowex 50WX8 adsorbent was characterized before and after sorption of metal ions using Fourier-transform infrared spectroscopy (FT-IR), Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray Analysis (EDX) techniques. Sorption parameters were studied which included contact time, initial metal ion concentration, nitric acid concentration and adsorbent dose. The equilibrium time has been set at about 15.0 min. The experimental results showed that the sorption efficiency of metal ions under the investigated conditions decreased with increasing nitric acid concentration from 0.50 to 3.0 M. The maximum sorption capacity was found to be 30.0, 50.0 and 60.0 mg/g for Pr(III), DY(III) and Y(III), respectively. The desorption of Pr(III) from the loaded resin was achieved with 1.0 M citric acid at pH = 3 and found to be 58.0%. On the other hand, the maximum desorption of Dy(III) and Y(III) were achieved with 1.0 M nitric acid and 1.0 M ammonium carbonate, respectively. The sorption isotherm results indicated that Pr(III) and Y(II) fitted with nonlinear Langmuir isotherm model with regression factors 0.995 and 0.978, respectively; while, Dy(III) fitted with nonlinear Toth isotherm model with R2 = 0.966. A Flow sheet which summarizes the sorption and desorption processes of Pr(III), DY(III) and Y(III) using Dowex 50WX8 from nitric acid solution under the optimum conditions is also given.

Improving heavy oil recovery, part (I): synthesis and surface activity evaluation of some novel organometallic surfactants based on salen-M complexes.

This study focuses on preparing a new family of organometallic surfactants based on five ion complexes, namely Co2+, Ni2+, Cu2+, Fe3+, and Mn2+. The first step is the preparation of 5-chloromethyl salicylaldehyde (Salen, S). The second step is the formation of sodium alkoxide of Pluronic F-127 (AP). The third step is the formation of the modified AP-Salen (new ligand). This ligand was reacted with the metal chlorides as mentioned earlier to obtain the organometallic surfactants (OMS) named AP-Salen-M complexes. FT-IR, 1H-NMR, SEM, and EDX justified the chemical structure of the as-prepared materials. The surface tension of these surfactants was measured for surfactant solutions at different concentrations to determine the CMC and calculate their surface-active properties. The interfacial tension at CMC was measured against heavy crude oil to predict the availability and use these surfactants in the enhanced oil recovery (EOR) process. From the results, this class of surfactants exhibited good surface-active properties and high efficiency on the interface adsorption; besides, they reduced the interfacial tension in the order between 10-1 and 10-2 mN m-1, which gives a good indication to use these surfactants in EOR application for the heavy crude oil.

The use of microwave plasma-assisted CVD on nanostructured iron catalysts to grow isolated bundles of carbon nanotubes.

Catalysts play a key role in the growth of carbon nanotubes. The microwave plasma-assisted chemical vapor deposition (MPACVD) method is now commonly used for directional and conformal growth of carbon nanotubes (CNTs) on substrates. In this work, we report on the effect of H(2) plasma pre-treatment on the diameter and density of iron catalyst nanoparticles for different iron layer thicknesses in order to grow isolated bundles of CNTs. Atomic force microscopy shows first that as plasma power density increases, iron nanoparticle diameters decrease, which is due to the increasing of gas dissociation giving more ion bombardment energy, and second that the diameter of nanoparticles decreases with the catalyst thickness. The growth of CNT was carried out under different CH(4) concentrations for different iron film thicknesses. Transmission electron microscopy and Raman spectroscopy show that the synthesized CNT were of good quality and had an outer diameter between 5 and 10 nm.

Challenges to laboratory hematology practice: Egypt perspective.

Laboratory hematology is an integral part of all clinical laboratories along the extensive healthcare facilities in Egypt. The aim of this review is to portrait the laboratory hematology practice in Egypt including its unique socioeconomic background, blood disease pattern, education and training, regulatory oversight, and the related challenges. Current practice varies widely between different parts of the healthcare system in terms of the range of tests, applied techniques, workforce experience, and quality of service. The national transfusion service (NBTS) in Egypt has been recently upgraded and standardized according to the World Health Organization (WHO) guidelines. Formal postgraduate education roughly follows the British system. Laboratory hematology specialization is achieved through 2-3 years masters' degree followed by 2-4 years doctorate degree in clinical pathology with training and research in hematology. Improvement of laboratory hematology education is recently undergoing a reform as a part of the modernization of higher education policy and following the standards developed by the National Quality Assurance and Accreditation Agency (NQAAA). Accreditation of medical laboratories is recently progressing with the development of the "Egyptian Accreditation Council" (EGAC) as the sole accreditation body system and training of assessors. Current laboratory system has many challenges, some are related to the inadequate system performance, and others are unique to laboratory hematology issues. The rapid technological advances and therapeutic innovations in hematology practice call for an adapting laboratory system with continuous upgrading.

An assay for the determination of sirolimus levels in the lymphocyte of transplant patients.

UNLABELLED: Both tacrolimus (TAC) and sirolimus (SRL) bind to the same immunophilin FKBP12; however, their mechanisms of action are distinct. SRL inhibits mammalian target of rapamycin (TOR), which is an enzyme critical to the immune function. TOR inhibition blocks the signal that mediates T-cell proliferation by preventing cell-cycle progression from G1 to S phase. Moreover, TOR inhibition results in a decrease in antibody production by blocking B-cell proliferation and maturation into antibody producing cells. The use of SRL has resulted in a decrease in the number of rejection episodes. As with other immunosuppressive agents, SRL can cause dose-related side effects, the most notable of which are hypercholesterolemia, hyperlipidemia, anemia, and thrombocytopenia. Thus, therapeutic drug monitoring to assess efficacy and toxicity has became a necessity. SRL blood levels do not correlate with its bioactivity and are affected by the concomitant use of other immunosuppressive drugs. To determine the bioactivity of SRL we have developed an assay to determine the level of Sirolimus per lymphocyte of transplant patients. The levels were correlated with lymphocyte count. METHODS: Whole blood samples from patients on SRL were collected in Ethylene Diamine Tetra-acetic acid (EDTA) vacutainer tubes. Immediately the lymphocytes from 2 mL of blood were separated using 1.5 mL of Ficoll gradient, by centrifugation for 30 minutes at 2500 RPM. The lymphocytes were washed three times with phosphate-bufferd saline and the pellet suspended in 150 microL of Middle East research institute (MERI) drug extraction solution (Beirut, Lebanon), which was then added to 300 microL of IMx solublizing reagent. The cytoplasmic SRL concentrations in lymphocytes were measured using kits supplied from Abbott diagnostics or by high-performance liquid tomography. A corresponding whole blood sample from each patient was used to measure blood levels. To determine the level per lymphocyte, the value obtained was divided by the number of lymphocytes and expressed as Pg/cell. A pharmacokinetic profile for both blood and lymphocytes was constructed for each patient using data corresponding to predose C(0), 1 hour (C(1)) and 2 hours (C(2)) after the dose. The lymphocyte enumeration for C(0), C(1), and C(2) was performed using the FACS Calibur Flow Cytometer from Becton Dickinson. The average dose was 2.86 +/- 1.27 mg/d with a C(0) = 8.05 +/- 4.24, C(1) = 21.9 +/- 8.9 ng/mL, and C(2) = 23 +/- 0.03 ng/mL. Although there was a significant correlation (P=.0975) between the dose and C(0), there was no correlation between the dose and C(0) level on the lymphocyte count P=.897. However, there was a strong correlation between SRL lymphocyte levels (pg/cell) and the lymphocyte count (r(2)=.6.06). The higher the concentration of the drug the lower the lymphocyte counts. The assay is sensitive to within 0.45 pg/cell, reproducible with a coefficient of variance (CV) of 6.4% within assay and 7.5% for intraassay.

Bioavailability of a new generic formulation of mycophenolate mofetil MMF 500 versus CellCept in healthy adult volunteers.

Several studies have revealed a decreased incidence of early graft rejection with the use of mycophenate mofetil (MMF). The cost of the drug is, however, prohibitive especially in developing countries with limited resources. We compared the pharmacokinetic profile of a new MMF generic formulation (MMF 500 batch number: 06T3001; Medis Tunis) with those of Cellcept, (batch number: M1427; Hoffmann La Roche, Switzerland) in healthy volunteers. The study was double-blinded to investigator and volunteers. It had a balanced randomized, two-treatment, two-period, two-sequence, single-dose, crossover, comparative oral bioavailability design in adult healthy human volunteers. The study was designed, performed, and monitored by CRO Transmedical s.a.l International (Beirut, Lebanon) in accordance with the Basic Principals defined in the US 21 CFR Part 312.20, and the principals enunciated in the World Medical Association Declaration of Helsinki. We included nonsmoking healthy volunteers between the ages of 22 and 45 years. The subjects were admitted to the hospital one night prior to blood sampling. After volunteers received the same dinner, they were fasted overnight and for 2 hours postdosing. At 8 am each person received a single oral dose of 500 mg of either formulation. Blood samples were collected to construct the pharmacokinetic profiles as follows: 0, 0.15, 0.30, 0.45 minutes and 1, 1.15, 1.30, 2, 4, 6, 10, 12, and 24 hours. Water and food intake were the same for all volunteers during the whole study period. Following an 8-day washout period, the subjects were crossed over. Plasma mycophenolic acid concentrations were determined using a high-performance liquid chromatography validated enzyme-linked immunosorbent assay-based method (TransMedical, Beirut Lebanon). Physical examinations, hematology, urinanalysis, serum chemistry tests, and liver enzymes were performed at screening and at the end of each period. Subjects were monitored for safety and adverse events throughout the study by two physicians (one from the hospital and one from TransMedical). The Cmax, Tmax, and AUC for MMF 500 were 10.14 ng/mL, 51.82 minutes, and 18.33 ng/mL/h vs 10.94 ng/mL, 49.09 minutes, and 17.46 ng/mL/h for CellCept, respectively. The 90% confidence intervals (LSM) of Cmax, Tmax, and AUC for MMF 500 were 92.7%, 105.6%, and 105%, respectively, which is within the Food and Drug Administration (FDA)-assigned range for immunosuppressive drugs (90% to 111%). These results indicated that the products are equivalent and switchable according to FDA rulings.

Cyclosporine lymphocyte maximum level monitoring in de novo kidney transplant patients: a prospective study.

OBJECTIVES: To determine prospectively the temporal variations of cyclosporine-A lymphocyte maximum level, whole blood maximum concentration, and total lymphocyte count in patients with de novo kidney transplantation. MATERIALS AND METHODS: Lymphocyte maximum level, whole blood maximum concentration, and total lymphocyte count were prospectively measured in 35 patients at 1, 2, and 3 months after kidney transplantation. Two groups--a biopsy-proven acute rejection group (REJ+) and a rejection-free group (REJ-)--were compared. RESULTS: Both groups had similar lymphocyte maximum levels, whole blood maximum concentrations, and total lymphocyte counts at the first month after transplantation. REJ+ patients had significantly lower lymphocyte maximum levels at 2 and 3 months (59+/-34 and 33+/-9 pg/Lc) and higher total lymphocyte counts (0.00204+/-0.00078x10(9)/L and 0.00203+/-0.00022x10(9)/L) when compared with their REJ- counterparts (87+/-56 and 63+/-30 pg/Lc, P<.05 and P<.007) and (0.00137+/-0.00074x10(9)/L and 0.0015+/-0.0006x10(9)/L, P<.02 and P<.003) respectively. Whole blood maximum concentrations were significantly higher in patients in the REJ+ group (2050+/-623 vs 1414+/-536 ng/mL, P<.02) at 2 months. At 3 months, the 2 groups were comparable (1158+/-340 vs 1365+/-525 ng/mL, P=NS). CONCLUSIONS: These results suggest that acute rejection is associated with a relatively low cyclosporine- A lymphocyte maximum level and high total lymphocyte count in the early posttransplant period. Cyclosporine-A whole blood maximum concentration failed to correlate with clinical outcome. Cyclosporine-A lymphocyte maximum level seems to offer a more reliable alternative than does whole blood maximum concentration for cyclosporine-A monitoring in patients with kidney transplantation.

Comparison between concentrations of trace elements in normal and neoplastic human breast tissue.

Histologically normal and neoplastic human breast tissues obtained from 25 patients at the time of mastectomy were homogenized (200 mg/ml) in distilled water and 5-microliter aliquots dried on Formvar films for trace element analysis by energy-dispersive X-ray fluorescence. The elements measured were calcium, vanadium, copper, zinc, iron, chromium, manganese, nickel, selenium, molybdenum, bromine, rubidium, strontium, mercury, arsenic, and lead. In general, significantly large increases (p less than 0.001) in calcium, vanadium, copper, zinc, selenium, and rubidium were found in breast tumors, with a less significant increase (p less than 0.05) for nickel. When a comparison was made between histologically normal and neoplastic tissues from the same individual, zinc and rubidium were found to be consistently higher in the tumor, whereas calcium, copper, and vanadium levels varied from normal to high. In no instance were the tissue changes in calcium, copper, zinc, or rubidium reflected in the blood levels, which were within normal limits. The distribution of calcium, copper, and zinc in urine varied among individuals with primary tumors; however, rubidium levels tended to be consistently elevated. An attempt is being made to correlate these various differences with the extent of the primary disease at the time of surgery, the postoperative tumor-free interval, and subsequent therapy.

Switchability of neoral and equoral according to Food and Drug Administration rules and regulations.

According to the US Food and Drug Administration (FDA), if a drug product contains a drug substance that is chemically identical and is delivered to the site of action at the same rate and extent as another drug product, then it is equivalent and can be substituted (switchable) for that drug product. Methods used to define bioequivalence as stated by the FDA rules (FDA 21 CFR 320, 24) are (1) pharmacokinetic (PK) studies in healthy volunteers, (2) comparative clinical trials, and (3) pharmacodynamic (PD) studies (bioactivity). We evaluated the switchability of Equoral (IVAX-USA) with Neoral (Novartis Switzerland using all FDA rules. In a single oral dose, we undertook a comparative bioavailability study of Equoral (IVAX, USA) Neoral (Novartis, USA), and Neoral (Novartis UK). The pharmacokinetics of Equoral and Neoral were determined with blood levels at 0, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 10, 12, 16, 24, 30, 36, 42, and 48 hours. The area under curve (AUC), AUC extrapolated to infinity (AUC0-inf), rate of absorption (Tmax), extent of absorption (Cmax), half time (t1/2) of Equoral and Neoral were all within the 90% confidence interval of 80% to 125% boundaries. A comparative multinational multicenter clinical trial in stable renal transplant patients included 70 patients (22 women and 48 men) of mean age of 33 years (range, 26 to 43) was performed in Turkey, Lebanon, and Pakistan. In this study the ratios of LSM and the 90% confidence intervals for the Nontransformed/Parameters (AUC0-t, AUCinf, Tmax, and Cmax) of Equoral and Neoral SGC were 98% and 95%, respectively, which are within the 80% to 125% FDA acceptance range. For immunosuppressive drugs, the site of action is the lymphocyte and the measurable response is the decrease in lymphocyte count caused by the relative concentration of the drug in the lymphocyte. In a controlled switch, fixed-dose study, both Equoral and Neoral achieved the same concentration in the lymphocytes and caused the same degree of lymphocyte count reduction. The results of the testing (bioavailability-bioequivalence, clinical studies, and pharmacodynamic-bioactivity) required by FDA for interchangeability ("switchability") of immunosuppressive agents suggests that Neoral and Equoral are switchable.

Late tissue reactions after single-fraction sequential half-body irradiation (HBI) in patients with non-Hodgkin's lymphomas.

Lung and hepatic toxicities constituted the main radiation-related damage after half-body irradiation (HBI) used as the treatment for patients with non-Hodgkin's lymphomas (NHL). Liver damage was mostly transient after a single dose of 8 Gy and could be well monitored by serum enzyme levels. A dose-response relationship could be shown for lung damage in the single dose range of 6.25-9.25 Gy, but the relationship did not reach statistical significance. A significant dose-rate effect could be shown. Mediastinal involvement by lymphoma seemed to increase the risk of pneumonitis. In a radical setting half-body irradiation is recommended to be used at a low dose-rate or as a multifraction irradiation in order to reduce the risk of liver and lung toxicities.

Testosterone-secreting adrenal adenoma that contained crystalloids of Reinke in an adult female patient.

We describe a testosterone-secreting adrenal adenoma that contained crystalloids characteristic of Leydig cells in a 55-year-old woman with virilization, in whom results of a steroid biochemical profile were normal except for a substantially increased serum testosterone level. After right adrenalectomy, the serum testosterone level returned to normal and has remained within the normal range 2 years postoperatively. Histologic examination confirmed the diagnosis of a testosterone-secreting adrenal adenoma with crystalloids of Reinke specific for Leydig cells. The exact pathogenesis of these testosterone-secreting adrenal adenomas is still unclear. Although crystalloids of Reinke have been identified in only three cases, their absence does not exclude a Leydig cell character in the rest of the reported cases. Our case provides additional support for the hypothesis that Leydig cells are present in the adrenal gland and may have an active role in the pathogenesis of testosterone-secreting adrenal tumors; thus, such cells should be sought in every case.

NMR imaging in the evaluation of orbital tumors.

The application of nuclear magnetic resonance (NMR) imaging to the diagnosis of orbital space-occupying lesions was studied in group of 28 patients with a wide range of pathology. The NMR findings in six patients are illustrated. The results of the NMR scans are compared with the information that can be derived from conventional neuroradiologic procedures, including computed tomography. The value of the multiplanar facility of NMR is emphasized. It provides accurate volumetric information and establishes the precise topographical relationships of tumors to normal structures. The muscle cone and the optic nerve can be identified in the axial, coronal, and sagittal planes. Current limitations of the method and possible future developments to improve diagnostic precision are discussed.

Surgical correction of senile entropion of the lower lid with fascia lata sling.

A method of surgical correction of senile entropion of the lower lid with heterogenous fascia lata sling is described with no tissue loss and minimum of surgical trauma.

Ofloxacin compared with chloramphenicol in the management of external ocular infection.

The safety and efficacy of 0.3% ofloxacin in treating bacterial ocular infections was compared with that of 0.5% chloramphenicol in a parallel-group, randomised clinical trial at five sites. Clinical and microbiological improvement rates were studied in 84 culture-positive patients. Patients with suspected bacterial ocular infections were evaluated for clinical improvement and were included in drug safety and comfort analyses. Clinical improvement did not differ significantly between drug treatments. All patients completing the study (79 assigned ofloxacin, and 74 chloramphenicol) showed clinical improvement. Clinical improvement in the culture-positive groups was 100% (41/41) after ofloxacin treatment, and 95% (41/43) after chloramphenicol treatment. Microbiological improvement rates were similar for the two drugs: 85% (33/39) improved with ofloxacin, and 88% (38/43) improved with chloramphenicol. Both drugs were well tolerated. Adverse reactions possibly due to the study medication occurred in 1% (1/89) of those who received ofloxacin, and in 4% (4/93) of those who received chloramphenicol.

The effect of dietary selenium deficiency on acute colorectal mucosal nucleotoxicity induced by several carcinogens in the rodent.

BACKGROUND: Selenium (SE) has been inversely associated with colon cancer risk. Two potential mechanisms of this effect were examined in a rodent short-term carcinogenesis assay: whether dietary SE deficiency altered the initiation aspect of carcinogenesis in the colon, and whether SE altered carcinogen metabolism. SETTING: Animal laboratory. SUBJECTS: 52 Sprague-Dawley rats, divided into a SE diet deficient group (0.002 parts per million; ppm) and a SE sufficient (0.2 ppm) group. ENDPOINTS: Weight, serum SE concentration, and karryorhectic index (KI), which is a measure of acute carcinogen induced nuclear toxicity in the colonic mucosa. METHODS: After three weeks of acclimation to the diets, eight animals from each dietary group were injected with one of the following: dimethylhydrazine (DMH), a colon specific carcinogen, its metabolite, methylazoxymethanol (MAM), or 0.9% sodium chloride. Twenty-four hours after injection the colons were removed, blood drawn, and the stained colons assayed for nuclear aberrations. RESULTS: No weight differences were generated by the dietary variations. Low-dietary SE resulted in serum SE declining markedly in the study period to 6 ng/ml versus 33 ng/ml in the SE sufficient group. Diet alone, and variations in weight gain, did not alter the KI. Both carcinogens greatly increased the KI in both the left and right colon. A SE-deficient diet was associated with a higher KI in both carcinogen groups in the right colon, with statistical significance for both the left and right colon in the MAM injection group. CONCLUSIONS: Dietary SE deficiency is associated with increased KI of the colon in MAM treated rats. SE, therefore, has a protective effect in the initiation phase of carcinogenesis.

Expression of the major mammalian stress protein in the rat cochlea following transient ischemia.

The transient expression of stress proteins in cells exposed to adverse environmental conditions is thought to provide a survival advantage. In the present study, the expression of the major mammalian stress protein, Hsp72, was characterized in the rat peripheral auditory system following varying periods of unilateral cochlear ischemia and reperfusion. Western blot analysis of whole cochlear homogenates revealed Hsp72 expression after as little as 5 minutes of cochlear ischemia. Cochlear Hsp72 immunoreactivity following 10 minutes of ischemia was observed within 2 hours, remained evident through 6 hours, and decreased toward control levels by 12 hours. Preliminary immunocytochemical localization data revealed Hsp72 expression in the outer hair cells. The characterization of Hsp72 expression following transient ischemia represents the first step toward understanding the role that stress proteins have in the protection of the mammalian auditory system.

Bilateral simultaneous orbital decompression for Graves' orbitopathy with a combined endoscopic and Caldwell-Luc approach.

Graves' orbitopathy can lead to cosmetic deformity, orbital pain, and visual impairment. Surgical intervention can improve proptosis, cosmetic appearance of the eyelids, vision, and orbital pain with minimal morbidity. Ten patients with dysthyroid orbitopathy underwent concurrent bilateral orbital decompressions. Of these, 9 underwent simultaneous bilateral endoscopic and transantral decompressions, and 1 had only bilateral endoscopic decompressions. Medical management of keratopathy was attempted before surgery. All patients were previously treated with radioiodine and high-dose corticosteroids, and 2 patients had prior low-dose orbital irradiation. Preoperative and postoperative visual acuity, color vision testing, and measurement of proptosis were recorded for all patients. In addition, photographs and CT scans of the orbit and sinuses were done. After surgery, visual acuity improved in 8 patients and remained unchanged in 2 patients. Diplopia in the primary and downward gaze improved in 1 patient and remained unchanged in the 3 others who had it before surgery. Color vision deficits in the blue/yellow range were present in 8 patients before surgery and all reversed within 2 weeks after surgery. Proptosis decreased by an average of 4.83 mm (range 4-7 mm) in patients undergoing the combined decompression and decreased by 4 mm in the 1 patient who had the endoscopic decompression only. Ethmoid sinusitis developed in 1 patient but resolved with oral antibiotics, and another patient had an asymmetric result requiring additional unilateral surgery, which corrected the asymmetry. Overall, this approach avoids external incisions and allows excellent visualization in the regions of the orbital apex and ethmoid roof, facilitating maximal decompression without the increased risk of bleeding or visual disturbances.