Growth patterns of fresh human crystalline lenses measured by in vitro photographic biometry

The purpose of the study was to demonstrate and evaluate the use of digital-image photography to measure the central thickness and equatorial diameter of whole fresh human crystalline lenses free of all zonular attachments. Forty-one human donor postmortem intact clear crystalline lenses, with a mean age of 28.5 +/- 16.4 years, were obtained by the contributing eye banks. The lenses were removed by the eye bank and shipped in Optisol-GS, a physiologic preservative storage medium, at 7 degrees C. The lenses were stored at the same temperature and in the same preservative throughout this study. This medium has been demonstrated to maintain the morphometric characteristics of epithelial cells. After freeing the lenses of all residual zonular attachments, digital photographs were obtained within an average of 20.9 +/- 13.4 h after death. The digital images were used to determine the central thickness and equatorial diameter of the crystalline lenses. By carefully calibrating the digital images and maintaining the lenses in physiological storage medium, reliable dimensional measurements were obtained. The dimensions for central thickness for each lens were compared to published, age-matched lenses, measured in vivo, and were found to duplicate these in vivo measurements reliably.     

Metabolic formation of pyrenequinones as enhancing agents of mutagenicity in Salmonella

Pyrene and 1-methylpyrene in the pyrolysis product of cellulose, which enhances mutagenicity of 2-acetylaminofluorene, must be metabolized to expose enhancing activity. 1,6-Pyrenequinone and 1,8-pyrenequinone, having high enhancement activity, were first isolated and identified in the metabolites of pyrene by rat liver microsomal fraction.     

Immunoprotein deposition in the cornea

A 63-year old woman had bilateral, multi-level corneal deposits distributed as fine, discrete crystals and in dense, deep geographic patches. She had a long history of sero-positive rheumatoid arthritis. Autopsy revealed an unsuspected lymphoproliferative disorder and immune-complex disease. Histologic examination of the eyes revealed eosinophilic, PAS-positive, noncollagenous deposits in the cornea at all levels and also in the ciliary processes, pars plana, and choroid. Stains for gold, amyloid, and acid mucopolysaccharides were negative. Immunoperoxidase stains were positive for IgG most strongly, and also for IgA, kappa and lambda light chains. Transmission electron microscopy showed needle-like electron-dense extracellular particles which we presume are immunoglobulins.     

Antibiotic granules for reconstitution as syrups: product uniformity and stability dependent upon reconstitution procedure

The penicillin content and stability of diluted antibiotic syrups, prepared according to the manufacturers' recommendations and other, non-approved, methods have been investigated. Methods which involve portioning the granules before reconstitution are hazardous and may result in preparations which range from very little antibiotic content to a double strength preparation. The choice of diluent controls the stability of the preparation. Phenoxymethylpenicillin syrups become less stable as the sucrose content increases. This is not always true with ampicillin syrups where the system is more complex. Although syrups prepared according to the manufacturers' instructions are not always the most stable, the effect of different diluents on the stability of syrups, especially suspensions, suggests that syrups should always be reconstituted and diluted according to the directions provided with the product.     

Treatment of the blastic transformation of chronic granulocytic leukemia using high dose BCNU chemotherapy and cryopreserved autologous peripheral blood stem cells

Seven nonsplenectomized patients with blastic CGL have received high dose BCNU chemotherapy followed by cryopreserved peripheral blood stem cells (PBSC). The PBSC obtained at diagnosis were stored in the vapor phase of liquid nitrogen in 10% dimethyl sulfoxide for 11-46 months prior to use. Patients received 2.9 X 10(8) (1.9-7.8) thawed washed mononuclear cells/kg over 30 minutes with minimal morbidity. One patient was not rendered pancytopenic and died with blastic leukemia at 4 months. One patient, previously treated with daily busulfan, died of progressive hepatic failure 2 months after high dose BCNU. Restoration of the chronic phase of CGL was observed in the remaining five patients. Peripheral blood counts returned to normal ranges after a median of 19 days. Median survival for all patients is 11 months. Cytogenetic studies revealed elimination of acquired aneuploid cell lines in four of seven patients with persistence of Ph1. We conclude that: 1) frozen PBSC retain their viability for up to 4 years after cryopreservation and 2) the use of autologous PBSC following ablative chemotherapy may be associated with both symptomatic and karyotypic improvement in patients with blastic CGL.     

Enhancement of hepatocellular genotoxicity of several mutagens from amino acid pyrolysates and broiled foods following ethanol pretreatment

The effect of subchronic ethanol ingestion on the genotoxicity and metabolism of the mutagens 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,5-b]indole (Trp-P-2), 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1), 2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and 2-amino-3,4- dimethylimidazo[4,5-f]quinoline (MeIQ) was evaluated in primary cultures of rat hepatocytes. Male Sprague-Dawley rats were pair-fed, for 8 days, liquid diets containing either ethanol (8%, v/v) or an isocaloric sucrose solution. Ethanol pretreatment significantly (P less than 0.05, Student's t test) enhanced the level of DNA repair stimulated by Glu-P-1, Glu-P-2, IQ and MeIQ. Statistically significant increases in DNA-repair activity ranged from 1.9-fold for IQ to 3.4-fold for Glu-P-2. Following a 16-hr exposure, the concentration of parent mutagen in the culture medium decreased by 75-98%. Neither the rate of mutagen metabolism in hepatocyte cultures nor the extent of mutagenic activation in microsome preparations was appreciably affected by ethanol pretreatment. The results suggest that ethanol pretreatment enhances the genotoxicity of Glu-P-1, Glu-P-2, IQ and MeIQ by inducing non-microsomal activation processes.     

Separation of pineal extracts by gelfiltration

Summary Aqueous extracts of sheep pineal bodies were separated on Sephadex G-25. Two low molecular weight Sephadex G-25 fractions, F 2 and F 3, were ultrafiltrated through the Amicon membrane UM-2. The UM-2 filtrate was subsequently filtrated through the ultramembrane UM-05 and the UM-05 filtrate was separated on Sephadex G-10 columns. After paper electrophoresis, preparative paper chromatography was carried out. The fluorescent band showing a Rf value identical with synthetic 6-biopterin was eluted; gas liquid chromatography and mass spectrometry of the isolated compound were carried out. The mass spectra of the isolated compound were shown to be identical with synthetic 6-biopterin.The results of theCrithidia fasciculata test and thinlayer chromatography study revealed that the isolated compound is identical with 6-L-erythro-biopterin.The activities of the isolated compound and of synthetic biopterin inin vitro andin vivo bioassays are demonstrated.     

Lack of soluble carbonic anhydrase in aortic smooth muscle of the rabbit

Rabbit aorta was investigated for the occurrence of soluble, methazolamide-sensitive carbonic anhydrase (CA) by measuring electrometrically the rate of acidification of a weakly alkaline CO₂ solution buffered with 12.5 mM veronal/HCl at 0°C. For this purpose, aortae of 10 rabbits with the endothelium carefully preserved, were homogenized, centrifuged, and the supernatants pooled. The proteins were fractionated by FPLC, and tested for their CA activity. In control experiments, the pH change resulting from the spontaneous CO₂ hydration was found to be –0.92±0.01 pH units/min (mean±SE,n=10). Aliquots of the 30,000 dalton protein fraction corresponding to 100 mg of aortic tissue wet weight did not alter the hydration rate significantly (–0.94±0.01 pH units/min,n=10). Also, in the presence of 10^–4 M of the CA inhibitor, methazolamide, these rates were not altered significantly (–0.94±0.01 and –0.93±0.01 pH units/min, respectively,n=10). No CA activity was found in the other FPLC fractions, either. — These results suggest that soluble CA is absent from the myocytes and the endothelium of the rabbit aorta.Supported by the Deutsche Forschungsgemeinschaft within the SFB 90 Cardiovasculäres System     

Gas‐Phase Assisted Surface Polymerization of Vinyl Monomers with Fe‐Based Initiating Systems

Summary: Gas‐phase assisted surface polymerization (GASP) of methyl methacrylate (MMA) and styrene (St) was investigated with Fe‐based radical initiating systems, FeCl₂/2,2′‐bipyridine (Bpy)/methyl α‐bromophenylacetate (MBPA), etc. GASP with these initiating systems proceeded to produce corresponding polymers on substrate surfaces. The resulting PMMA had very high PDI values, suggesting an uncontrolled reaction. In an attempt to control the GASP, polymerization with a simple initiating system, Fe(0)/MBPA, was examined on Fe(0)‐metal surfaces, resulting in significant polymerization activity to produce high‐molecular‐weight PMMA. The results of time‐course tests on GASP of MMA and St suggested that a change had taken place to produce physically controlled propagation sites on the Fe(0) powder surfaces.

GASP schemes with a simple initiating system Fe(0)/MBPA.     

A shift of visual spatial attention is selectively associated with human EEG alpha activity

Event-related potentials and ongoing oscillatory electroencephalogram (EEG) activity were measured while subjects performed a cued visual spatial attention task. They were instructed to shift their attention to either the left or right visual hemifield according to a cue, which could be valid or invalid. Thereafter, a peripheral target had to be evaluated. At posterior parietal brain areas early components of the event-related potential (P1 and N1) were higher when the cue had been valid compared with invalid. An anticipatory attention effect was found in EEG alpha magnitude at parieto-occipital electrode sites. Starting 200 ms before target onset alpha amplitudes were significantly stronger suppressed at sites contralateral to the attended visual hemifield than ipsilateral to it. In addition, phase coupling between prefrontal and posterior parietal electrode sites was calculated. It was found that prefrontal cortex shows stronger phase coupling with posterior sites that are contralateral to the attended hemifield than ipsilateral sites. The results suggest that a shift of attention selectively modulates excitability of the contralateral posterior parietal cortex and that this posterior modulation of alpha activity is controlled by prefrontal regions.