Application and limitations of chloromethyl-benzamidodialkylcarbocyanine for tracing cells used in bone Tissue engineering

Bone tissue engineering has the potential to provide us with an autologous bone substitute. Despite extensive research to optimize the technique, little is known about the survival and function of the cells after implantation. To monitor the cells, in vivo labeling is the method of choice. In this study we investigated the use of the fluorescent membrane marker chloromethyl-benzamidodialkylcarbocyanine (CM-Dil) to label cells used in bone tissue engineering. When applying label concentrations up to 50 microM, cells could be labeled efficiently without negative effects on cell vitality, proliferation, or bone-forming capacity. Porous hydroxyapatite scaffolds were seeded with labeled cells, and up to 6 weeks after implantation in nude mice cells could be traced inside tissue-engineered bone. However, contrary to other reports concerning intramembranous labels, transfer of the label from labeled to unlabeled cells was detected. Transfer occurred both in vitro and in vivo between vital cells and between dead and living cells. To determine when in vivo label transfer happened, devitalized, labeled constructs were implanted for various time periods in nude mice. The presence of vital labeled cells inside these constructs, when evaluated at different implantation periods, indicated transfer of the label. Transfer occurred at 7 days postimplantation when 40 microM label was applied, whereas 10 microM labeled constructs showed transfer 10 days after implantation. These findings indicate that CM-Dil label is useful for in vivo tracing of cells for follow-up periods up to 10 days. This makes the label particularly useful for cell survival studies in tissue-engineered implants.     

The role of cholesterol on the pressure sensing ability of kidneys in rats

We studied the effect of hypercholesterolemia on the pressure-sensing and regulating ability of the kidneys, using an acute hemorrhage model to provide 40% and 60% reduction in the blood pressure of hypercholesterolemic and control rats. The control group (n = 22) was fed a normal rat pellet diet and tap water; the experimental group (n = 22) received a diet containing 2% cholesterol/0.2% thaurocholate. Half the animals were subjected to 6 mL/kg bw and the others to 12 mL/kg bw of bleeding for 1 min. Blood pressure recording and proper samplings were done before bleeding and during the 20 min post-hemorrhagic period for analysis. Despite a finding of hypercholesterolemia in the experimental group, kidney cholesterol content as well as its function remained unchanged. Following an initial 40% decrease in rats bled 6 mL/kg bw, 20 min later the mean blood pressure returned to 90% of its initial value in control rats and to 70% of its basal level in hypercholesterolemic rats. A similar delay in pressure normalization occurred in rats subjected to 12 mL/kg of bleeding. Plasma renin activity remained unaffected. We conclude that dietary hypercholesterolemia delays the normalization of blood pressure after hemorrhage without affecting the sensing ability of kidneys, and that the kidneys are less sensitive than other organs to plasma cholesterol levels.     

Interaction of intraocular lenses with various concentrations of silicone oil: an experimental study

The aim of this study was to evaluate the interaction between various widely used intraocular lenses (IOLs) and silicone oils of different viscosities. Four groups of IOLs, including monoblock foldable hydrophilic acrylic IOLs (Morcher, type 92s); monoblock hydrophobic acrylic IOLs (Acrysof-SA60AT, Alcon); single-piece rigid polymethylmethacrylate (PMMA) IOLs (Intraocular Optical International-IOI-65130) and a three-piece foldable silicone optic IOL (CeeOn Edge 911A, Pharmacia UpJohn) were analyzed in vitro to determine the percentage adherence 1,000-centistoke, 1,300-centistoke or 5,000-centistokes silicone oil on the IOL optic. For each IOL type, there was no statistically significant difference in the mean silicone oil coverage (MSC) of the IOL optics for the different viscosities of silicone oil. Silicone IOLs had the highest MSC percentage (79.9%) whereas hydrophilic acrylic IOLs were the least silicone-covered IOLs (7.8%) compared to the other IOL types tested in this study. It is not the concentration of silicone oil that affects silicone oil coverage. When performing small-incision cataract surgery in patients who may require silicone oil injection, foldable hydrophilic acrylic or hydrophobic acrylic lenses should be preferred over standard foldable silicone lenses.     

Unilateral Purtscher-like retinopathy after weight-lifting

PURPOSE: To report a case of Purtscher-like retinopathy after weightlifting. METHODS: A 17-year-old man presented with a sudden visual loss in his left eye after weightlifting two weeks ago. Fundus examination of the left eye showed cotton-wool spots and scattered retinal hemorrhages in the posterior pole. Fluorescein angiography and indocyanine green angiography with a scanning laser ophthalmoscope were performed. RESULTS: Angiography showed hypofluorescent areas adjacent to the optic disc and in the posterior pole and partial filling insufficiency in the inferior and inferotemporal branch retinal veins. Complete venous filling was noted in late phases of angiography. CONCLUSIONS: The pathogenesis of weightlifting suggests the Purtscher-like changes as a result of Valsalva maneuver in our case. To our knowledge, this is the first reported case of Purtscher-like retinopathy associated with weightlifting.     

Management of free floating iris cysts in the anterior chamber: a case report

PURPOSE: To present a case with free iris cysts in the anterior chamber and its management with YAG laser. CASE REPORT: A 14-year-old boy presenting with the complaint of seeing a small ball-like moving mass in his left eye. RESULTS: Slit-lamp examination revealed a pair of free-floating iris cysts located inferiorly in the anterior chamber. After YAG laser application both the cysts collapsed. CONCLUSIONS: This is the first report of a case with multiple free iris cysts in the anterior chamber. Considering the possibility of endothelial damage in the long-term, it is worth noting the favorable response to YAG laser treatment.     

Investigation of acute toxicity of deltamethrin on guppies (Poecilia reticulata)

Deltamethrin, a synthetic pyrethroid pesticide contaminating aquatic ecosystems as a potential toxic pollutant, was investigated in the present study for acute toxicity. Guppy fish (Poecilia reticulata) were selected for the bioassay experiments. The 48-h LC50 was determined for the guppies. The experiments were repeated three times and a total of 210 guppies were used. The static test method of acute toxicity test was used. In addition, behavioral changes at each deltamethrin concentration were determined for the individuals. Data obtained from the deltamethrin acute toxicity tests were evaluated using the Probit Analysis Statistical Method. The 48-h LC50 value for guppy was estimated as 5.13 microg/L.     

Silent stroke in a case of beta-thalassemia major associated with chronic renal failure and diabetes mellitus

Severe anemia, growth retardation, diabetes mellitus, cardiac disorders, and, infrequently, stroke are well-known complications of thalassemia major. We report a girl, age 7 years, 2 months, with beta-thalassemia major associated with chronic renal failure, diabetes mellitus, and cardiomyopathy in whom a silent stroke was noted during follow-up. She was diagnosed with thalassemia major at age 6 months, chronic renal failure at age 3 years, 3 months, and diabetes mellitus and cardiomyopathy at age 7 years. Although cranial computed tomography was found to be normal at the age of 3 years, 3 months, magnetic resonance imaging showed cerebral infarct in the right frontal region at 7 years, 2 months. A thrombophilic panel revealed increased factor VIII and decreased protein C concentrations. She died from disseminated intravascular coagulation at age 7 years, 9 months. We did not record any clinical findings of stroke during her follow-up. We think that diabetes mellitus, dilated cardiomyopathy, and increased factor VIII and decreased protein C concentrations led to the occurrence of cerebral infarct. In conclusion, we emphasize that children with thalassemia major should be monitored closely for stroke. We also suggest that stroke can show a silent progression in severely affected children, as in our case.     

Electromyographic biofeedback in the treatment of the hemiplegic hand: a placebo-controlled study

OBJECTIVE: To evaluate the efficacy of electromyographic (EMG) biofeedback treatment in the functional recovery of the hemiplegic hand. DESIGN: A total of 27 patients were randomly assigned to EMG biofeedback or placebo EMG biofeedback groups. Both treatments were applied five times a week for a period of 20 days. In addition, the patients in both groups received an exercise program according to the Brunnstrom's neurophysiologic approach. Goniometric measurements for wrist extension, scale for judging the performance of drinking from a glass, Brunnstrom's stages of recovery for hand, and surface EMG potentials were used for the clinical assessments. All patients were assessed before treatment and after 20 treatment sessions. RESULTS: The results showed that there were statistically significant improvements in all variables in both groups, but the improvements in active range of motion and surface EMG potentials were significantly greater in the EMG biofeedback group at the end of the treatment. CONCLUSION: Our study demonstrates the potential benefits of EMG biofeedback in conjunction with neurophysiologic rehabilitation technique to maximize the hand function in hemiplegic patients.     

Penetration of amikacin into aqueous humor of rabbits

Amikacin is an aminoglycoside antibiotic that has poor corneal penetration due to its hydrophilic properties. The purpose of this study was to compare and evaluate the penetration of amikacin sulfate into aqueous humor of the rabbit eye when applied by different routes and concentrations, namely 100 or 250 mg/ml topical fortified amikacin eye drops, 100 or 250 mg/ml amikacin-embedded soft contact lenses and 25 mg subconjunctival amikacin injection. One hour after application, amikacin was not detectable in any of the 100 mg/ml concentration groups. High levels of amikacin above the minimum inhibitory concentration for susceptible bacteria were detected when applied subconjunctivally and by 250 mg/ml topical fortified routes. Topical fortified amikacin 250 mg/ml reached the highest value in the aqueous (p < 0.05). Our results point out the poor corneal penetration of amikacin in standard concentrations from the intact rabbit cornea and that subconjunctival injections might provide satisfactory penetration.