Longitudinal changes in subjective and objective visual function 5 years after cataract surgery Prospective population-based study

PURPOSE: To investigate the long-term outcomes of cataract surgery by analyzing data collected 5 years after surgery and comparing with preoperative and postoperative subjective and objective visual function results. SETTING: Norrlands University Hospital, Ume?, Sweden. METHODS: A prospective longitudinal population-based cohort study comprised 810 patients who had cataract surgery during a 1-year period within a geographically defined area. Evaluated were visual acuity data and Visual Function-14 questionnaire (VF-14) results before and after surgery. Five years later, the 590 patients still alive were offered eye examinations and asked to fill out the questionnaire. RESULTS: Of the 590 patients asked to participate at 5 years, 530 answered the questionnaire and 467 had eye examinations. The median VF-14 total score for all patients after surgery was 100; at 5 years, the score decreased to 96.7 (P = .001). Five years after surgery, 46% of patients had unchanged or better visual acuity in the operated eye, 37% had lost more than 0.1 logMAR unit, and 22% had a reduction in VF-14 score of 10 points or more. The two main reasons for the decline in visual acuity and VF-14 scores were age-related macular degeneration (ARMD) (47% and 60%, respectively) and glaucoma (12% and 11%, respectively). Age, co-morbidity, and VF-14 scores after surgery were independently associated with the VF-14 score 5 years after surgery. CONCLUSIONS: Subjective and objective visual function 5 years after cataract surgery remained stable in most patients. Co-morbidity, most commonly ARMD, was the most frequent cause of deterioration of visual acuity and decrease in VF-14 scores. Age and co-morbidity were independently associated with the VF-14 score 5 years after surgery.     

The effects of gastroenteroanastomosis, antral exclusion and antral resection on the enterochromaffin cells in the rat gastrointestinal tract

The effects of gastroenteroanastomosis, antral exclusion and antral resection on the enterochromaffin (argentaffin) cell system in the rat alimentary tract were studied 6 weeks after the operation. When measured as cell density per mm3 mucosa, the number of enterochromaffin cells was decreased in most gastrointestinal regions following the three surgical procedures. In the antral exclusion group this decrease was most apparent in the caecum and large intestine, and in the animals with antral resection it was most pronounced in the proximal and middle regions of the small intestine. When expressed per segment mucosa, the enterochromaffin cells were even more reduced in number in all three experimental groups, as a result of mucosal atrophy in the entire gastrointestinal tract. The atrophy was most pronounced in animals with gastroenteroanastomosis, and least pronounced in those with antral exclusion. The underlying mechanisms of the effects on the enterochromaffin cell system under these experimental conditions are discussed.     

Maternal blood volume in placenta of the rhesus monkey measured in vivo by positron emission tomography

The relative volume of the intervillous space of the placenta of the rhesus monkey was measured in vivo using positron emission tomography (PET), a noninvasive tracer technique. 11CO-Hb and 68GaCl3 were both used in three experiments and 68Ga-EDTA in two. The tracers were administered intravenously as bolus doses to 6 pregnant monkeys during 7 different pregnancies. Measurements with 11CO-Hb gave a volume of 48.0% of the total placental volume. Transplacental transfer of 11CO to the fetal circulation is probably a minor problem due to the small fetal blood volume and the prolonged time before the same concentration is reached in the maternal and fetal blood. Measurements with 68GaCl3, which binds to transferrin, gave an intervillous space volume of 55.6% of the placental volume. The concentration of radioactivity in the placenta did not attain a steady state, indicating a clearance of the tracer from the blood only to a small extent. Measurements with 68Ga-EDTA displayed a volume of 60.4% of the placental volume. Transplacental transfer and the additional distribution of radioactivity to fetal and maternal extracellular spaces, including the placenta, when 68Ga-EDTA was used will make this tracer unsuitable in measurements of the blood volume of the placenta with PET.     

Studies on the activation of rat liver microsomal glutathione transferase in isolated hepatocytes.

The mechanism of activation of microsomal glutathione transferase in isolated liver cells by diisapropylidene acetone (phorone) was investigated. Phorone (1 mM) causes a time-dependent increase (up to 2.6-fold) in the glutathione transferase activity of microsomes isolated from treated hepatocytes. Since phorone reacts with sulfhydryl groups, the possibility that this compound activated microsomal glutathione transferase directly was studied. It was found that neither the activity of the purified enzyme nor that in isolated microsomes is affected by phorone. It has been suggested [Masukawa T and Iwata H, Biochem Pharmacol 35: 435-438, 1986] that activation of microsomal glutathione transferase by phorone in vivo is mediated through thiol-disulfide interchange involving oxidized glutathione (GSSG). It is shown here that the glutathione transferase activity of isolated microsomes, which was increased by the addition of 10 mM GSSG, can be decreased to the basal level with 0.1 M dithioerythritol. Dithioerythritol, on the other hand, only marginally decreases the glutathione transferase activity in microsomes isolated from phorone-treated hepatocytes. This finding argues against a role for thiol-disulfide interchange in the activation of the enzyme by phorone. Furthermore, the glutathione depletion caused by phorone does not seem to be responsible for activation per se, since other thiol depletors [e.g. diethylmaleate (DEM)] do not affect the activity of the enzyme. Immunoblot analysis of microsomes isolated from phorone-treated hepatocytes did not reveal any partial proteolysis which might have accounted for the activation. It is suggested that activation of microsomal glutathione transferase by phorone proceeds through a mechanism which might reflect an in vivo regulation of this enzyme. Additional compounds which have been shown to activate the microsomal glutathione transferase in vivo were also tested and significant activation was obtained with 1,2-dibromoethane (1.4-fold) but not with DEM or carbon tetrachloride. Activation was also obtained with 1-chloro-2,4-dinitrobenzene (CDNB) (1.6-fold) and to a small extent with t-butyl hydroperoxide (1.2-fold). The activation by 1,2-dibromoethane and CDNB is probably mediated through covalent binding, considering the known alkylating properties of these compounds. CDNB is the first substrate shown to activate the microsomal glutathione transferase implying that electrophilic compounds which are substrates can increase the rate of their own elimination by reacting with this enzyme. In addition, activation by t-butyl hydroperoxide indicates that oxidative stress can activate microsomal glutathione transferase.     

A 3-year clinical study of alternatives to high noble dental casting alloys type 3

For the purpose of evaluating the quality of dental casting alloys, 22 patients were recalled for clinical examination 3 years after insertion of crowns and bridges made from the low-gold alloy Midas and the silver-palladium alloy Albacast. A high-gold alloy, JS C, served as a reference alloy. The examination included registrations of tarnish, plaque index, gingival index, and margin index. In addition, the California Dental Association's quality evaluation of dental care was used by two independent calibrated examiners. From the results of the present study it can be concluded that the crowns made from the alloy Midas in the annealed condition and the alloy Albacast are well suited for clinical use. Some tarnish appeared, but this may occur intermittently.     

Staining of rat thyroid parafollicular (C-) cells with the Sevier-Munger silver technique

The argyrophil silver stain of Grimelius and of Sevier-Munger was studied in rat thyroid parafollicular (C-) cells after formation and Bouin fixation. The strongest and most easily reproducible staining reaction was obtained in tissue fixed with Bouin's fluid and stained by the Sevier-Munger technique. The identify of the argyrophil cell as the calcitonin-containing C-cells was established by re-staining the same sections with calcitonin antibodies according to the method of Sternberger.     

Regional distribution of the opioid receptor agonist N-(methyl-11C)pethidine in the brain of the rhesus monkey studied with positron emission tomography

The regional distribution and kinetics in the brain of Rhesus monkeys of N-(methyl-11C)-pethidine have been studied by positron emission tomography, PET. 11C-Pethidine reached the brain with peak radioactivities appearing within 6-10 min. after administration. Highest radioactivities were measured in areas corresponding to the thalamus, the striatal area and also the lowest transection of the temporal lobes, with an uptake of 2.7-3.1 times the homogenous dilution of the radioactive dose. Low radioactivities were seen in the cerebellum and the occipital lobes. This distribution corresponds to the regional density of opioid receptors using in vitro binding techniques. The 11C-pethidine derived radioactivity left the brain with an initial half-life of 40-60 min., followed by an elimination which paralleled the plasma elimination of unlabelled pethidine. After pretreatment of the monkey with a small dose of naloxone, the radioactivities decreased about 40% in areas corresponding to the thalamus, striatum and lowest section of the temporal lobes, indicating competition for the same binding sites. By the use of a three-compartment model, it was possible to get an estimate of 11C-pethidine receptor binding characteristics in the brain. The ratio of Kon/Koff, equal to Bmax./Kd, was 0.06-0.1. This indicates that pethidine is bound with low affinity to the opioid receptors and is a poor ligand for studies of opioid receptor function with PET. Brain kinetics of 11C-pethidine is mainly determined by its blood kinetics.     

Antipyrine clearance during experimental and occupational exposure to toluene.

Exposure to toluene vapour enhances hepatic microsomal enzyme function in animals as assessed by the metabolism of the test drug antipyrine. Thirty six printing trade workers with long term occupational exposure to a mixture of organic solvents and 39 matched controls were randomly allocated into four groups. Eighteen printers and 21 controls were exposed to 100 ppm of toluene during 6.5 hours in an exposure chamber. The remaining 18 printers and 18 controls were exposed to 0 ppm of toluene under similar conditions. The salivary clearance of antipyrine was measured immediately after the stay in the exposure chamber to investigate a possible acute change in liver function and was repeated two weeks later, shortly before the summer vacation. Antipyrine clearance was measured again at the end of the summer vacation-four weeks after exposure. To study a possible effect of chronic exposure on antipyrine clearance 12 printing trade workers with 17 years (median) of occupational exposure to toluene vapour at concentrations of about 100 ppm were investigated before and four weeks after cessation of exposure. No difference in antipyrine clearance was found either within the groups or between the groups at any of the measurements.     

Middle ear effusion in children and the indoor environment: an epidemiological study

A prospective study of 337 children was carried out during a 3-month period. The purpose of the study was to evaluate the importance of indoor environmental factors in homes and day-care institutions for the incidence of middle ear effusion (MEE). The indoor environmental factors measured in institutions were carbon dioxide, temperature, and relative humidity. Conditions in the homes were assessed by a questionnaire. Middle ear effusion was measured by tympanometry. No relationship was found between indoor environmental factors and MEE, with the exception of parental smoking at home, which increased the frequency of MEE in children.     

Renal effects of acute exposure to toluene. A controlled clinical trial

Urinary excretion rates of beta 2-microglobulin and albumin were measured in 43 male printing trade workers and 43 age-matched male controls before and during exposure to toluene, 382 mg/m3, for 6 1/2 hours in a climate chamber. There were no significant changes in renal excretion rates of albumin and beta 2-microglobulin during toluene exposure indicating that no causal relationship exists between moderate exposure to organic solvents and renal injury.