A dolichol acyltransferase present in rat and human postheparin plasma.

Incubation of small unilamellar vesicles consisting of dioleoyl phosphatidylcholine-dioleoyl phosphatidylethanolamine (3:1) and 2 mol% [3H]dolichol-19 with postheparin plasma from rat resulted in the formation of dolichyl oleate. Normal plasma or heat-treated postheparin plasma contained no activity and, hence, the results indicate the presence of a cell surface associated dolichol acyltransferase that can be released into the blood by heparin. The reaction is strongly stimulated by phosphatidylethanolamine and Ca2+, whereas no stimulation with triglycerides or acyl-CoA was observed. Together with the fact that the only product formed was dolichyl oleate, these results strongly suggest that a transacylation mechanism from the phospholipids to dolichol is operative in the liposomes. Gel chromatography of postheparin plasma yielded a molecular mass of about 350 kilodaltons for the active enzyme and density gradient centrifugation indicated that this high molecular mass complex consists mainly of proteins. Finally, we conclude that this enzyme is not unique to the rat, but is also present in human postheparin plasma.


Uptake of dolichol by Vero cells.

Characterization and kinetics of dolichol uptake by a Vero cell line are reported. Vero cells incorporate dolichol in a time- and dose-dependent manner. Optimal uptake is found at 37 degrees C and at a pH of 7.4. In contrast to cholesterol, an inhibitory effect on the dolichol incorporation is found for farnesol, geraniol, and retinol. Long chain polyprenols were slightly stimulatory. The translocation seems not to be highly energy dependent. The lack of substantial inhibition by chloroquine does not plead for a receptor-mediated endocytosis. Incorporated dolichol was distributed over both membranes and supernatant fractions, paralleling the distribution of the lysosomal marker beta-N-acetylhexosaminidase. The incorporated dolichol is subject to a fast efflux process, which is potentiated by the presence of lipid acceptors in the extracellular medium.


Blood dolichol in lysosomal diseases.

Highly elevated serum total dolichol (free dolichol + dolichyl ester) concentrations have recently been found in two lysosomal storage diseases, aspartylglucosaminuria (AGU) and mannosidosis. The present study demonstrates that the increase of serum dolichol in AGU patients is caused by an increase of serum free dolichol. In 15 patients the mean serum level of free dolichol (227 +/- 16 ng/mL) was 1.9 times higher (p < 0.001) than that in healthy controls (120 +/- 6 ng/mL), while the amounts of dolichol fatty acid esters were similar in the patients and controls (110 +/- 9 vs. 118 +/- 6 ng/mL). In contrast, 10 patients with neuronal ceroid-lipofuscinosis (NCL) (three with infantile, four with juvenile, and three with variant late infantile NCL) had significantly (p < 0.01) lower mean serum levels of both free (79 +/- 5 ng/mL) and total (159 +/- 6 ng/mL) dolichol than age-adjusted healthy controls (free, 100 +/- 6 ng/mL; total, 206 +/- 14 ng/mL). Decreased blood dolichol has not been reported earlier for any other disease. We conclude that the increased serum free dolichol in AGU reflects disturbed lysosomal function and that the decreased free and esterified dolichols in NCLs speak against their presumed primary lysosomal nature.


Rat liver lysosome membranes are enriched in alpha-tocopherol.

The subcellular distribution of alpha-tocopherol has been studied in rat liver. Lysosomal membranes were found to be considerably enriched in alpha-tocopherol with 6300 pmol/mg membrane protein, whereas mitochondrial membranes and microsomes contained 530 and 200 pmol/mg membrane protein, respectively. The 37-fold higher specific content of alpha-tocopherol in lysosomal membranes relative to homogenate indicates that lysosomes could be a target of cellular pathology in vitamin E deficiency states.


Protein-linked isoprenoid lipids in dexamethasone-treated human lymphoid lines in culture.

Accumulation of isoprenoids was studied in two cell lines derived from acute T-cell leukemia: CEM-C7 cells, whose growth is inhibited by the glucocorticoid dexamethasone, and CEM-C1 cells, which are resistant to this steroid. Isoprenoids were measured by growing the cells in serum-free medium in the presence of lovastatin, which blocks synthesis of mevalonate, and then labeling with exogenous [3H]mevalonolactone. In both cell lines, isoprenoids associated with proteins were detected in cytoplasm, nucleus, and chromatin, and in the chromatin residue that remains after extraction of histone and nonhistone proteins. Differences in labeling were detected after treatment with dexamethasone in the CEM-C7 line, showing a decrease in the cytoplasmic fraction with a corresponding increase in both the nuclear and chromatin fractions as compared with untreated cells. No change was seen in the CEM-C1 line. In both cell lines, 25-30% of the incorporated label was released by treatment with acid or alkali. However, the majority of the label required treatment with methyl iodide for the release of organic-soluble tritiated products. After extraction with chloroform, the lipid fractions contained farnesol, geraniol, dolichols, and possibly nerolidol.


Localization and preferred orientations of ubiquinone homologs in model bilayers.

The localization of ubiquinone has been investigated in phospholipid bilayer vesicles in studies of fluorescence quenching of membrane-bound probes by ubiquinone homologs (Qn, where n is the number of the isoprenoid units of the chain). Fluorescence-quenching data obtained by using a set of anthroylstearate probes, having the fluorophore located at different depths, revealed that ubiquinone-3 is located throughout the whole bilayer thickness. From the bimolecular quenching constants in the membrane, lateral diffusion coefficients in two dimensions were calculated to span values of 10(-7)-10(-6) cm2.s-1. This suggests that ubiquinones laterally diffuse in a very fluid environment. On this basis, it is proposed that their translational diffusion in the bilayer takes place in two dimensions, with the quinone ring oscillating between the two bilayer surfaces within a hydrophobic environment not extending beyond the glycerol region. This model implies that the quinonic head is both settled near the polar surface of the bilayer and buried into the host hydrocarbon interior. This two-site distribution was confirmed for all Qn, except Q0, by their linear dichroism spectra in the bilayers provided by disc-like lyotropic nematic liquid crystals. These spectra also provided detailed information on the preferential orientations of the quinonic head of the different derivatives within the two sites. The mechanism by which the localization and orientation of Qn guest molecules inside the host bilayer is modulated by the isoprenoid chain length is discussed on a thermodynamical basis. Being that Qn is expected to be also widely contained in the highly curved cristae of the mitochondrial inner membrane, by using rod-like lyotropic nematic liquid crystals we searched out effects of the curvature of the host bilayer on those Qn distributions. The linear dichroism measurements reveal that Qn guest molecules are no longer obliged to find a partition between two different types of localizations when the host bilayer is highly curved. In this case all Qn, even the longest Q10, were found to stay parallel to the amphiphilic chains with a single site localization of the head near the polar interface. By the same linear dichroism technique, the local ordering of all Qn derivatives was also evaluated. The order parameters were found to be basically the same for all derivatives. This result is justified on the basis of the relaxation, caused by the surface curvature, of the lateral compression of the host chains.


Dolichyl-pyrophosphoryloligosaccharide protein oligosaccharide transferase in neuronal ceroid-lipofuscinosis.

The kinetics of the oligosaccharide transfer from oligosaccharyl pyrophosphoryldolichol to endogenous protein acceptors in human fibroblasts were studied. No alterations in the transferase activity and enzyme characteristics could be observed in fibroblasts from neuronal ceroid-lipofuscinosis (NCL) patients. Analysis of urinary dolichol of two NCL patients also did not reveal substantial differences with respect to controls.


Partition of free dolichol in human urine.

We have demonstrated that dolichol is present in the urinary supernatant. Most of the dolichol present in the supernatant seems to be associated with cellular debris or membrane fragments. The amount of sediment in healthy subjects correlate well with the volume of urine. Although it is illogical to express urinary dolichol relative to urine volume, a good correlation between the amount of sediment and urine volume has made its use justifiable. Because of the presence of a substantial amount of dolichol in the supernatant, it seems better to use uncentrifuged whole urine as the sample for measurement of dolichol.


Particulate glycogen of mammalian liver: specificity in binding phosphorylase and glycogen synthase.

The glycogen particle - glycogen metabolizing enzyme complex was investigated to gain some understanding of its physiological significance. Fractionations of populations of particles from mouse liver were carried out utilising open column and high performance liquid chromatography, and based either on the molecular weight of the particles or the hydrophobic interactions of the glycogen-associated proteins. The activities of glycogen phosphorylase and glycogen synthase were measured in these fractions. Fractionations were of tissue in different stages of glycogen deposition or mobilization. In animals fed ad libitum, glycogen synthase was associated with the whole spectrum of molecular weights, while the glycogen phosphorylase distribution was skewed in favour of the lower molecular weight species. Under conditions of glycogen mobilization, the phosphorylase distribution changed to include all molecular weights. The hydrophobic interaction separations demonstrated that glycogen synthase binds to a specific subpopulation of particles that is a minor proportion of the total. In general, there was a direct relationship of the total amount of phosphorylase and synthase bound during periods of mobilization and deposition, respectively. Two notable exceptions were the large amounts of glucose-6-P dependent synthase present during the early period of glycogen mobilization and the high amounts of active phosphorylase appearing shortly after food withdrawal, in spite of interim glycogen deposition from presumably already ingested food.


Modification of mRNA-associated proteins during changes in growth conditions.

Following serum stimulation of quiescent 3T6 cells, an elevated in vivo rate of translation was observed. These studies were designed to identify the proteins associated with polysomal mRNA under different growth conditions in an attempt to establish a relationship between translational rate and the mRNA-associated proteins. Ultraviolet cross-linking of proteins to mRNA was employed to ensure that only genuine mRNA-associated proteins were investigated. Our results revealed little change in the population of mRNA-binding proteins, although minor variations in the synthesis of several proteins, most notably a 32 kilodalton species, were observed during growth transitions. These investigations demonstrate further that most of the mRNA-binding proteins were phosphorylated with the degree of phosphorylation of several proteins influenced by growth conditions.


Hepatic heparan sulphate proteoglycan and the recycling of transferrin.

Heparan sulphate proteoglycan, labelled with [35S]sulphate, was prepared from rat livers for studies of its interaction with purified rat transferrin. Affinity chromatography of the preparation on columns of immobilized differic transferrin and apotransferrin showed that the proteoglycan possessed affinity for both types of matrices at pH 7.3 and that this affinity significantly increased at pH 5.6. The glycosaminoglycan chains liberated from the proteoglycan by heparan sulphate lyase also bound to apotransferrin, albeit less strongly, whereas the deglycosylated core protein exhibited virtually no interaction with this matrix. In the presence of the proteoglycan at pH 5.6, the release of iron from the N-lobe of transferrin was accelerated. These observations suggest that heparan sulphate proteoglycan from the liver can mimick some of the known functions of bona fide transferrin receptors and, hence, interaction with the proteoglycan may provide an alternative nondegradative pathway for transferrin through hepatic cells.


Proliferation is required for induction of terminal differentiation of Friend erythroleukemia cells.

The relationship between cell proliferation and differentiation has long been a source of controversy. Stimulation of normal erythroid maturation results in a finite number of cell divisions accompanied by a concomitant accumulation of hemoglobin. Friend erythroleukemia cells treated with hexamethylene bisacetamide differentiate in a similar manner, while agents such as hemin apparently induce differentiation without limiting cell proliferation. Aphidicolin, an inhibitor of DNA synthesis, has been reported to induce differentiation in the absence of cell proliferation. Using these three chemicals we have investigated the relationship between cell proliferation and erythrocytic maturation by exposing Friend erythroleukemia cells to either hexamethylene bisacetamide (5 mM), hemin (100 microM), or aphidicolin 1.2 microM) and examining the effects on cell growth, morphology, and hemoglobin production. Proliferation in the presence of hexamethylene bisacetamide is limited to four to five rounds of cell division, while hemin has no inhibitory effect. Hexamethylene bisacetamide initiates the complete erythrocytic maturation program, including cellular structural changes and hemoglobin synthesis. Hemin stimulates only globin gene transcription, not differentiation. Aphidicolin inhibits cell growth within 24 h, but does not induce differentiation. Furthermore, inhibition of proliferation by aphidicolin prevents subsequent hexamethylene bisacetamide induced differentiation. These results indicate that at least one round of cell division is required for initiation of erythrocytic differentiation.


Secretion of SPARC by endothelial cells transformed by polyoma middle T oncogene inhibits the growth of normal endothelial cells in vitro.

Endothelioma cells expressing the polyoma virus middle T oncogene induced hemangiomas in mice by the recruitment of nonproliferating endothelial cells from host blood vessels (Williams et al. 1989). I now report that SPARC, a Ca(2+)-binding glycoprotein that perturbs cell-matrix interactions and inhibits the endothelial cell cycle, is produced by endothelioma cells and is in part responsible for the alterations in the morphology and growth that occur when nontransformed bovine aortic endothelial cells are cocultured with endothelioma cells. Normal endothelial cells cocultured with two different middle T-positive endothelial cell lines, termed End cells, exhibited changes in shape that were accompanied by the formation of cell clusters. Media conditioned by End cells repressed proliferation of normal endothelial cells, but enhanced that of an established line of murine capillary endothelium. Radiolabeling studies revealed no apparent differences in the profile of proteins secreted by aortic or capillary cells cultured in End cell conditioned media. Characterization of proteins produced by End cells led to the identification of type IV collagen, laminin, entactin, and SPARC as major secreted products. Although SPARC did not affect the morphology of End or capillary cells, it was associated with overt changes in the shape of aortic endothelial cells. Moreover, SPARC and a synthetic peptide from SPARC domain II inhibited the incorporation of [3H]thymidine by aortic cells, but had minimal to no effect on the capillary endothelial cell line. The inhibition of growth exhibited by aortic endothelial cells cultured in End cell conditioned media could be partially reversed by antibodies specific for SPARC and SPARC peptides. These studies indicate a potential role for SPARC in the generation of hemangiomas by End cells in vivo, a process that requires normal (host) endothelial cells to disengage from the extracellular matrix, withdraw from the cell cycle, migrate, and reassociate into the disorganized cellular networks that comprise cavernous and capillary hemangiomas.


Increased preproenkephalin A gene expression in the rat heart after induction of a myocardial infarction.

The expression of preproenkephalin A (ppENK) gene was investigated in the rat heart, following the onset of myocardial infarction induced by ligation of the left anterior descending coronary artery. The relative abundance of ppENK mRNA and the level of enkephalins were measured by Northern blot analysis and radioimmunoassay, respectively, in the ventricles from control-unoperated, sham-operated, and operated rats. Three hours after the surgery, a comparison between rats with infarction and sham-operated rats revealed that the relative abundance of ppENK mRNA and the level of enkephalins were increased three- to four- and two- to three-fold, respectively, in the ventricles of rats with infarction. No difference was observed between rats with infarction and sham-operated rats 24 h after the surgery, or between rats with infarction compared at time intervals of 3 and 24 h following the surgery. The abundance of the ppENK mRNA in the polysomal fraction of the ventricular septum was also measured 3 h after the surgery and found to be threefold higher in rats with infarction as compared with sham-operated rats. These results indicate that the level of enkephalins rapidly increases in the ventricles of rats following myocardial infarction, and that this higher level may be ascribed to a stimulation of the local synthesis of enkephalins.


Accelerated entry of aortic smooth muscle cells from spontaneously hypertensive rats into the S phase of the cell cycle.

The present study was designed to characterize the growth kinetics of the exaggerated proliferative response to mitogens of vascular smooth muscle cells from spontaneously hypertensive rats compared with cells from normotensive Wistar-Kyoto controls. Cellular DNA content, analyzed by flow cytometry, demonstrated a 4-h accelerated entry into the S phase of the cell cycle of vascular smooth muscle cells from spontaneously hypertensive rats; the significant (4.5-fold) increase in the percentage of cells in the S phase occurred between 8 and 12 h after calf serum stimulation. A 3.9-fold increase of cells in the S phase was seen in the normotensive controls only between 12 and 16 h. Transit through the cell cycle was quantitated by flow cytometry using the Hoechst 33,342--bromodeoxyuridine substitution technique. Vascular smooth muscle cells from spontaneously hypertensive rats went through the cell cycle 4 h ahead of cells from normotensive Wistar-Kyoto rats. This accelerated transit of spontaneously hypertensive rat cells was mostly due to an earlier entry into the S phase. Persistence of this new intermediate phenotype in cell culture suggests its primary pathogenetic role in spontaneous hypertension.


Transport of Ca2+ by diltiazem across the lipid bilayer in model liposomes.

The calcium channel antagonist diltiazem was examined for its ability to translocate Ca2+ from an aqueous medium to the nonpolar lipid milieu. We monitored the spectral changes caused by the drug-mediated cation transport at 37 degrees C in unilamellar vesicles made of dimyristoyl phosphatidylcholine (DMPC) and containing the calcium-sensitive dye arsenazo III trapped inside. Vesicle leakage or membrane fusion caused by diltiazem was assessed by the use of vesicles containing fluorescent indicators. These effects were, however, found to be insignificant compared with ion transport. The transport was negligible at temperatures below the liquid crystalline to gel transition temperature of DMPC indicating a carrier mechanism of ion transport. A quantitative analysis of the transport kinetics indicated that a 1:2 Ca(2+)-drug complex is formed inside the lipid. The calcium ionophoretic ability of diltiazem, combined with other related data, suggests a possible role for Ca2+ in the conformation of the drug in the lipid membrane milieu and in its interaction with the calcium channel.


Effects of nonenzymatic glycation of subfragment-1 of myosin on interactions with actin.

Nonenzymatic bonding of reducing sugars to subfragment-1 of myosin (S-1) resulted in a reduction in actin-activated S-1 ATPase activity. Fructose caused a greater reduction than glucose. The Km for binding of actin to S-1 was significantly increased with sugar derivatization. In addition, sugar derivatization lowered the ability of S-1 to promote polymerization of G-actin. Western blot analysis demonstrated that glucose was nonenzymatically incorporated into the 50 and 20 kilodalton (kDa) fragments of S-1 with preponderance in the 20-kDa fragment. The reduced affinity of derivatized myosin for actin is indicated by the increased Km, the reduced ability to stimulate actin polymerization, and the positive Western blot reaction in the 20-kDa fragment.


Assessment of basic cognitive abilities in relation to cognitive deficits.

A modal model of information-processing was used to select a battery of nine tasks of basic cognitive ability (learning, relearning, reaction time, probe recall, Sternberg search, self-paced probe, stimulus discrimination, tachistoscopic full report, tachistoscopic partial report). Parameters from these tasks operationalized the model. After extensive pilot testing of the tasks to establish reliability, we tested 40 subjects (20 with mental retardation and 20 college students) on all tasks and the WAIS-R. The parameters from the tasks were generally reliable (.7 through .9) and had low correlations with IQ (average about .37). Nearly all of the major cognitive parameters differentiated significantly between groups. A subset of the basic cognitive parameters predicted IQ with an estimated multiple correlation in the general population of .72. Prediction of IQ using basic cognitive parameters was better for subjects with mental retardation than for college students. A modified version of the modal model was supported. Results show that individual differences in higher mental processes are highly dependent on basic cognitive abilities and can be predicted from them. These findings have substantial implications for the development of models of information-processing.


Teaching self-instruction utilizing multiple exemplars to produce generalized problem-solving among individuals with severe mental retardation.

Four residents of a group home who had severe mental retardation were taught to use self-instruction in combination with multiple exemplars to solve task-related problems. The combined strategy was associated with generalization to untrained problems as well as response maintenance of the problem-solving strategy (i.e., responding to multiple exemplars and self-instructing). The use of the strategy was discussed in terms of instructional strategies for teaching self-instruction and areas for future research, including isolating the factors responsible for generalization and identifying the role of language in promoting generalized responding.


Families of children with mental retardation: comprehensive view from an epidemiologic perspective.

Data covering a 15-year period on the health, behavior, and functioning of a representative population of families of children with mental retardation and comparison children were used in cluster analysis to obtain relatively homogeneous groupings of families. Only a small minority of families of children with mental retardation did not cluster together with comparison families. More than a third functioned well and had a middle-class orientation; less than a third functioned poorly. A few clusters had ambiguous configurations, but most were easily understood and conformed generally to expectations in validation analyses.


General slowing of information-processing by persons with mental retardation.

On measures of speeded performance, persons with mental retardation typically respond more slowly than do those without mental retardation. A review of 45 published studies yielded 518 pairs of response times (RTs) in which each pair consisted of a mean RT for a group of persons with mental retardation for an experimental condition and the corresponding mean RT for a group of persons without mental retardation. The primary result was that RTs of individuals with mental retardation increased linearly as a function of RTs for persons without mental retardation in corresponding conditions. These results are consistent with the view that differences in processing speed between persons with and without mental retardation reflect some general (i.e., nontask specific) component of cognitive processing. Possible candidates for the general component were discussed.


Sentence processing by adolescents with and without mental retardation.

A more thorough test of the hypothesis that persons with mental retardation are less likely to construct semantically integrated representations of sentences that they hear than are subjects without mental retardation (Merrill & Bilsky, 1989; Merrill & Mar, 1987) was provided. A series of sentences were presented to adolescents with and without mental retardation. Their memory for the object nouns of the sentences was then tested when they were provided with either the subject noun, the verb, or the subject plus verb of the sentence as a retrieval cue. The two-word cue was relatively better if an integrated semantic representation was constructed. Manipulations included decreasing the processing time given to subjects (expected to inhibit the construction of integrated representations) and presenting a picture with the sentence (expected to facilitate the construction of integrated representations). The reduction in time decreased performance for the subjects without mental retardation to the level normally observed for those with mental retardation; presenting a picture increased performance of subjects with mental retardation to the level of comparison subjects. Results support the suggestion that previously observed differences in sentence processing between individuals with and without mental retardation may be due to differences in generating integrated representations of the sentences during processing.


[Occlusive treatment of atrophic and erosive oral lichen planus with Clobetasol Propionate 0.05% ointment (Dermovat)].

The treatment of eight patients with histologically verified atrophic or erosive lichen planus are reported. The lesions of WHO-diagnosis code 697.02 were subdivided into three classes: atrophic, minor erosive and major erosive. Clobetasol Propionate ointment was placed in the buccal mucosa under an occlusive DuodermR dressing. Healing with striation was obtained in all of those lesions classified as atrophic or minor erosive, while major erosive lesions showed improvement, but persisted.


[Fracture induced constriction treated by Continuous Passive Motion (CPM)].

Aspects of the history of treatment of painful joints are commented upon. It is pointed out, that the medical and dental professions have for more than 125 years been aware, that immobilization of joints may have harmful effects. Still, research on therapeutic motion of painful joints dates back only 25 years. A case is reported of fracture associated constriction, possibly due to secondary involvement of the temporalis muscle and especially its tendineous insertion on the muscular process of the mandible. When the patient was treated with the CPM apparatus Mobilimb J1 the interincisal distance increased from 13 mm to 46 mm. According to literature CPM has so far been used only as adjunctive physical therapy after surgical intervention. On the basis of data in the literature the author is studying the effect of CPM on reduced mobility of the jaws as primary treatment without surgery.


[Resorbable Vicryl mesh for new attachment after jaw fracture].

The principle of GTR, guided tissue regeneration, was developed by Scandinavian scientists in order to separate epithelium and connective tissue from periodontal ligament cells and bone, thereby eliciting new attachment after marginal periodontitis. In case of jaw fractures loss of attachment may be seen in relation to teeth in the line of fracture, especially after severe dislocation of the fragments. One such patient is reported in whom only emergency treatment was possible during the first 11 days due to a simultaneous cerebral trauma. As anticipated a deep osseous pocket developed on the actual tooth 43 even if the fractures were anatomically repositioned and fixed with osteosynthesis and even if the postoperative course was uneventful. Later, treated by interpositioning of a resorbable Vicryl membrane, new attachment formed with a gain of the order of magnitude of 8 mm with concomitant osseous regeneration. It is concluded that Vicryl mesh would definitely seem to have a place in the treatment of jaw fractures. However, there is an urgent need for a larger collection of meshes than presently available, including both larger sizes and other shapes.


The feeling of a presence and verbal meaningfulness in context of temporal lobe function: factor analytic verification of the muses?

We hypothesized that the feeling of a presence, particularly during periods of profound verbal creativity (reading or writing prose or poetry), is an endemic cognitive phenomenon. Factor analyses of 12 clusters of phenomenological experiences from 348 men and 520 women supported the hypothesis. We conclude that periods of intense meaningfulness (a likely correlate of enhanced burst-firing in the left hippocampal-amygdaloid complex and temporal lobe) allow access to nonverbal representations that are the right hemispheric equivalents of the sense of self; they are perceived as "a presence." The relevance of our results to the theories of Jaynes, Bear, Edelman, and MacLean is discussed.


Asymmetries in the spatial localization of transformed targets.

This study was designed to examine the contribution of the right cerebral hemisphere in the spatial localization of visual targets for manual aiming. Visual targets were briefly presented to the right and left fields and subjects were required to point either to the target location, or a "mirror" image of the target location with their right or left index finger. Whereas reaction times were faster for left-hand pointing than for right-hand pointing, there was no differential effect of the mirror image transformation. This suggests that left-hand reaction time advantages are more related to right hemisphere involvement in the spatial parameterization of the movement than spatial localization of the target.


Ideational fluency in Parkinson's disease.

Recent research on Parkinson's disease (PD) suggests that executive functions are impaired but that visuospatial functions may be spared. This dissociation has been attributed to dysfunction in ascending dopaminergic pathways affecting the prefrontal cortex. We investigated these ideas in a sample of intellectually intact patients with idiopathic, optimally treated PD (N = 20) and in spouse controls (N = 15); the groups were divided into young (age < 60) and old subgroups, each comparable on education, vocabulary level, and Mini-Mental State scores. Six tasks were selected from a set of factor-referenced cognitive tests to measure three abilities: (1) ideational fluency (ability to generate ideas), (2) flexibility of use (ability to shift mental set), and (3) spatial orientation (ability to perceive spatial patterns). PD patients were impaired only on the ideational fluency factor (p = .01). An age-related deficit was seen on the spatial factor (p < .05) with a trend on the flexibility factor (.05 < p < .10). No interactions were significant. The findings suggest that when age and verbal intelligence are controlled, PD patients show no deficit on purely spatial tasks; in contrast, patients seem less able to generate ideas though capable of shifting from one idea to another.


Assessment of the relationship of cerebral hemisphere arousal asymmetry to perceptual asymmetry.

This study examined the hypothesis that characteristic individual differences in cerebral hemisphere arousal asymmetry are related to individual differences in perceptual asymmetry observed in verbally based visual half-field tasks. The study used electrophysiological measures of arousal asymmetry rather than behaviorally derived measures (Levy, Heller, Banich, & Burton, 1983). Measures of alpha asymmetry were obtained from 20 right-handed males during a baseline relaxation condition and during a visual half-field version of the lexical decision task. Reaction time measures of perceptual asymmetry were obtained during this task. The results indicated that a basal arousal asymmetry measured at the temporal recording location during the baseline condition was significantly related to individual perceptual asymmetry during the subsequent lexical decision task. This basal arousal asymmetry was relatively stable across different task conditions. A task-related arousal asymmetry measured at the parietal location during the lexical decision task also made a significant contribution in predicting individual perceptual asymmetry. These two measures of individual arousal asymmetry were able to predict 50% of the variance in perceptual asymmetry. The implications of the results for explaining more wide-ranging individual differences in behavioral style and personality are discussed.


Electroencephalogram asymmetry during emotionally evocative films and its relation to positive and negative affectivity.

The purpose of the present study was to determine if there were differences in hemispheric lateralization during the experience of emotions and if those differences were related to personality style. College-age adult subjects selected for high positive and negative affectivity on Tellegen's Multidimensional Personality Questionnaire (MPQ; Tellegen, 1982) viewed video stimuli selected for their emotionally evocative nature and rated the intensity of the emotions they experienced. The ongoing electroencephalogram (EEG) was recorded while they watched the video clips. Analyses of the EEG data revealed that there were differences in regional activation during the emotional video clips, especially for those stimuli selected to elicit either happy or disgust emotions. These results support the hypothesis that the right hemisphere is specialized for the experience of certain negative affects, whereas the left hemisphere is specialized for the experience of certain positive affects. The findings also indicated some support for the theory that individual differences in personality style are related to differing levels of hemispheric arousal.


The roles of handedness and stimulus asymmetry in aesthetic preference.

When some pictures are mirror reversed, aesthetic evaluations of them change dramatically. Stimulus features that may be important in contributing to this effect are: (a) location of areas of principal interest or weight in the picture space, (b) cues that suggest a direction of motion within the picture. Dextrals and inverted sinistrals preferred paintings with cues suggesting motion proceeding from left to right over their mirror-reversed versions and also preferred those with weight concentrated in the left portions of the picture space. The explanation that best fits these data is that preference is promoted when the picture content encourages attention to its rightmost portions, thus placing a majority of the picture in the left visual field where it is directly processed by the right hemisphere.


Visual hemispheric asymmetries depend on which spatial frequencies are task relevant.

Observers classified sine-wave and square-wave gratings on the basis of fundamental frequency (Are the bars wide or narrow?) or on the basis of higher harmonic frequencies (Are the bars sharp or fuzzy?). Stimuli were presented in either the left (LVF) or right (RVF) visual field. When the classification was made on the basis of the fundamental frequencies (1 or 3 c/deg), there was a LVF/right hemisphere advantage. However, when the classification was on the basis of a sharp/fuzzy distinction which involved searching for the higher harmonic frequencies, then a RVF/left hemisphere advantage was found.


Auditory/verbal and visual/spatial memory in children with complex partial epilepsy of temporal lobe origin.

Two groups of epileptic children and a normal control group were administered a Comprehensive Children's Memory Scale (Experimental Edition) which is presently being developed by this author. The first experimental group consisted of 12 children having complex partial seizures of left temporal origin and the second group consisted of 12 children having partial complex seizures of right temporal lobe origin based upon clinical description and EEG/neuroimaging verification. Results indicated: (a) Children with left temporal lobe epilepsy demonstrated significantly lower performance than controls on auditory/verbal memory testing. (b) Children with right temporal lobe epilepsy demonstrated significantly lower performance than controls on visual/spatial memory testing. (c) For the most part, the right and left temporal lobe groups did not significantly differ from each other. However, their performance was in the expected direction; i.e., children with left temporal lobe epilepsy scored lower than right temporal lobe epileptics on auditory/verbal memory testing, and children with right temporal lobe epilepsy scored lower than left temporal lobe epileptics on visual/spatial memory testing.


Impaired drawing from memory in a visual agnosic patient.

A case is reported of an associative visual agnosic patient who could not draw from memory objects he could recognize, even though he could copy drawings flawlessly. His ability to generate mental visual images was found to be spared, as was his ability to operate upon mental images. These data suggest that the patient could generate mental images but could not draw from memory because he did not have access to stored knowledge about pictorial attributes of objects. A similar functional impairment can be found in some other visual agnosic patients and in patients affected by optic aphasia. The present case allows a discussion of relationships among drawing from memory, imagery, and copying procedures.


The organization of arithmetic facts in memory: evidence from a brain-damaged patient.

We report a single case study of a brain-damaged patient with impaired arithmetic performance. Three principal findings are presented: First, in a task involving production of answers to simple arithmetic problems, the patient's performance was far better for subtraction than for addition or multiplication. Second, in all arithmetic operations performance was generally much better for problems potentially solvable by rule (e.g., 5 + 0) than for problems requiring retrieval of specific facts (e.g., 5 + 3). Third, the dissociation between subtraction and the other arithmetic operations obtained in the production task was not observed in a verification task. The implications of these findings for claims concerning the organization of stored arithmetic facts are discussed.


Fluency versus conscious recollection in the word completion performance of amnesic patients.

To examine the relative contribution of fluency and recollection to the word completion performance of amnesics, we administered a task in which patients were told specifically not to utilize previously presented words during stem completion (an Exclusion condition). This condition was contrasted with a standard word completion task in which patients were encouraged simply to complete the stem with the first word that came to mind (an Inclusion condition). Since the exclusion condition necessitated controlled respecification of the initial presentation, it was hypothesized that amnesics would be less able than controls to exclude study list items. Consistent with this hypothesis, the results indicated that the amnesics' performance, unlike that of the alcoholic controls, did not significantly differ as a function of task condition. To examine whether amnesics' conscious recollection could be enhanced, Experiment 2 presented the study list five times. The amnesics now were able to exclude a significant number of items from the study list; however, they still did so considerably less frequently than alcoholic controls. For the alcoholic controls, increasing the number of study trials had little additional effect on their exclusion performance, but it significantly enhanced their inclusion performance. Taken together, these findings suggest that for control subjects, word completion performance is likely mediated by a combination of fluency and recollection, while for amnesic patients, performance is almost exclusively based on the fluency with which an item comes to mind.


Gall's psychophysiological concept of function: the rise and decline of "internal essence".

Gall did not employ the term "function" to refer to adaptive mental processes or to observable behavior. To the contrary, he and the phrenologists took a traditional concept of function regarding the contribution or duties of a part within the overall "animal economy" and argued that the "faculties" of the soul are among the functions of the nervous system. In particular, he brought this psychophysiological use of the term into his Enlightenment perspective when he aligned it with internal essence, juxtaposed it to its external sign, and argued that the cerebral organs are the material instruments through which the internal faculties manifest themselves in behavior and in the shape of the skull. Gall did not believe that the faculties are a product of the organs but that the organs, being material incarnations of the internal functions, contain the power to express the faculties externally. Purely psychological uses of function are infrequent among the works of Gall and his followers. It was not until the functionalists at the turn of the century that the word was applied to the adaptive utility of mental processes in relation to the environment and not until the advent of behaviorism that it was employed to refer to the end or adaptive utility of a particular behavior.


Hemispheric specialization for word classes with visual presentations and lexical decision task.

In the present paper we study the possible RH capabilities for the processing of adjectives and verbs of high frequency and medium imagery using a lexical decision task and a horizontal display. In the analysis of both RTs and mean errors, a RVF advantage is obtained. The interaction VF x Word Class did not reach significance. Therefore, we did not find evidence of differences in the visual-field effect for any syntactic class. These results support a LH superiority for the processing of both adjectives and verbs. For the nonword conditions (pseudoverbs and pseudoadjectives), no visual field differences were observed in either group. Methodological aspects are also discussed.


Phenotypic similarities between Stargardt's flavimaculatus and pattern dystrophies.

Some heredomacular diseases share ophthalmoscopic and morphologic similarities despite being nosologically distinct. In part, this may arise from pathologic reaction patterns such as lipopigment accumulation and drusen deposition which are common to a variety of disorders of the photoreceptor--retinal pigment epithelium--Bruch's membrane complex. Two of these disorders, Stargardt's flavimaculatus and the pattern dystrophies of the retinal pigment epithelium may be especially difficult to differentiate clinically since they are characterised by both a similar ophthalmoscopic appearance and considerable inter and intrafamilial variation in their expression. Stargardt's flavimaculatus may, however, be distinguished from the retinal pigment epithelial pattern dystrophies by certain clinical and morphological features that are outlined below.


Leber hereditary optic neuropathy in Australia.

Leber hereditary optic neuropathy (LHON) presents with sudden onset of visual loss mainly in young adult males. LHON is not uncommon in Australia, accounting for 2% of invalid blind pensions. We have identified 20 unrelated families carrying mitochondrial DNA mutations associated with LHON and 135 of 291 individuals with documented LHON are currently alive in Australia. The mean age of onset of visual loss for males was 26 years and for females 27 years, with a range from six to 65 years. The mean risk of visual loss was 20% for males and 4% for females. There are over 1750 male and female carriers living in Australia who have not yet lost vision; 600 carriers are under 24 years of age. The expected number of new cases of blindness from LHON is three to four per year.


The objective assessment of abnormal eye movements in infants and young children.

Recordings of eye movements from infants and young children can be of clinical value in patients with certain neuro-ophthalmological problems. This requires that the characteristics of normal eye movements in this same age-group are known. Using an electro-oculographic technique in a specially developed laboratory we have been able to assess the saccades, binocular and monocular smooth pursuit, binocular and monocular optokinetic nystagmus (OKN), and sustained vestibular rotation in infants and young children; these recordings were performed in one session lasting approximately 35 minutes. The recordings from four children with abnormal eye movements (delayed visual maturation, hemicerebral cyst, congenital ocular motor apraxia, and gaze-paretic nystagmus) are briefly reported and compared to normal eye movements of age-related children. The limitations of this procedure are discussed.


The development of fixing and focusing behaviour in normal human infants as observed with the Otago photoscreener.

The Otago photoscreener is an optical instrument which gives a very sensitive indication of the accuracy with which a subject's eyes are fixing and focusing. Early experience suggested that this instrument could be used effectively to screen for the presence of amblyogenic factors in pre-verbal infants. This communication describes the development of ocular fixation and focusing in 137 normal infants who were followed at regular intervals during the first year of life. Accurate fixation and focusing was found in 13% of three-month-old infants, in 68% of six-month-old infants and in 76% of one year olds. The levels of 'focusing' visual acuity obtained from the photoscreen data are considerably better than the levels of cortical acuity measured by the standard behavioral and electrophysiological methods. This suggests that human infants fix and focus accurately for a considerable period before they are able to perceive all the details obtained in their retinal images.


Familial congenital corneal anaesthesia.

Congenital corneal anaesthesia is a cause of severe corneal ulceration and scarring in childhood. Although uncommon, it may be underdiagnosed when present as an isolated entity. Measures such as the use of elbow splints and tarsorrhaphy may be necessary to prevent visual loss. In rare instances, the condition may be inherited. A family is presented with autosomal dominant isolated congenital corneal anaesthesia, and the systemic associations and treatment of the condition are reviewed.


A clinical and cytological study of vitamin A deficiency in Kiribati.

Vitamin A status was assessed clinically and by conjunctival impression cytology in a selected group under seven years of age in the Republic of Kiribati. A total of 230 children were studied. Of 185 with readable histology, 14.6% were clinically and histologically abnormal; 19.5% were clinically abnormal but histologically normal; and 15.7% were clinically normal and histologically abnormal. The remainder (50.3%) were clinically and histologically normal. There was a significant correlation between clinical disease and histology (P < 0.001). The prevalence of the disease in males was 45.8% and 26.3% in females. The risk of deficiency appeared to increase with advancing age. There was no significant difference between the two villages studied.


An abbreviated assessment of ocular exposure to ultraviolet radiation.

Individual behaviour has a very large effect on determining the exposure of the eye to solar radiation. To be able to examine the relationship between ocular exposure to ambient ultraviolet radiation and ocular disease, a model was developed previously that assessed cumulative ocular exposure from individual information on work and leisure activities. In this paper, we present a simplified version of the model that uses data on exposure during the middle of the day (9 a.m. to 3 p.m. solar time) during the northern 'summer' months (April to September). The ocular exposure determined by the simplified model is highly correlated with the full model (r = 0.98) and the simplified model predicts 62% of the total ocular exposure. This model should be useful for future epidemiologic studies of sun exposure and eye disease.


Development of experimental chronic intraocular hypertension in the rabbit.

There are many unanswered questions about chronic glaucoma which cannot be investigated in the available animal models. The present experiments were designed to develop a rabbit model of chronic intraocular hypertension with characteristics similar to human chronic glaucoma by ligating vortex veins or by making single or multiple intraocular injections of 0.5% or 1% alpha-chymotrypsin, 20% chondroitin sulphate, 2% hydroxypropyl methylcellulose, 2% sodium carboxymethylcellulose or 1% or 2% methylcellulose. Evaluation was based on the clinical findings, intraocular pressure and the retrograde axoplasmic transport function of the optic nerve using a horseradish peroxidase histochemical technique. Most methods either failed to produce moderate chronic intraocular hypertension or were associated with other complications. However, a reliable and relatively long period (eight weeks) of intraocular hypertension was developed by a series of four intra-anterior chamber injections of 1% or 2% methylcellulose. This model has been proved suitable for the study of structural and functional damage to the retina and optic nerve caused by chronic glaucoma.


The effect of cataract extraction with implant in glaucomatous eyes.

The effect of cataract surgery in patients with glaucoma controlled by either topical medication or surgery was assessed in 64 patients. At one year there was a small significant fall in intraocular pressure (IOP) for eyes without previous surgery (preoperative IOP 18.9 +/- 4.7, range 12 to 35 mmHg; postoperative IOP 16.3 +/- 3.4, range 10 to 26 mmHg; P < 0.01) and also for those with previous surgery (preoperative IOP 15.0 +/- 4.3, range 3 to 22 mmHg; postoperative IOP 14.2 +/- 3.7, range 6 to 22 mmHg, P < 0.05). There was a significantly greater incidence of high rise in IOP to 30 mmHg or more immediately after operation in patients without (32%) than those with previous surgery (13%) (chi 2 = 3.9; P < 0.05). Complications were minimal in each group. Iridotomy to deliver the nucleus was necessary in nine eyes without and 21 with previous surgery. Cataract extraction usually causes only a small fall in IOP in glaucomatous patients. If a separate corneal section is used there is no loss of function of the filtering bleb in patients with previous glaucoma surgery.


The results of combined cataract extraction and trabeculectomy using separate incisions.

A method of combined cataract extraction with posterior chamber intraocular lens and trabeculectomy using separate incisions was tested in 44 operations on 38 patients. The mean preoperative intraocular pressure (IOP) of 28.1 +/- 11.7 (range 12 to 56) mmHg on maximum medication was lowered to 13.9 +/- 3.4 (9 to 23) mmHg at one year, with half the eyes still requiring topical medication. The IOP was 40 mmHg or more preoperatively in eight eyes and 20 mmHg or more in only two patients at one year. There were no rises in IOP above 20 mmHg in the early postoperative period (days 1 and 2). Visual acuity was 6/9 or better in 27 and 6/12 in three eyes. There was an expulsive haemorrhage in one case, rupture of the posterior capsule in two eyes and a choroidal detachment in one eye, but no flat anterior chambers. The two-incision method allowed placement of an intraocular lens with good post-operative pressure control.


Day-surgery external dacryocystorhinostomy.

A retrospective study of patients undergoing day-surgery external dacryocystorhinostomy (DCR) over five years is presented. The patients were medically fit for day-surgery, preferred outpatient to inpatient care, and had appropriate domiciliary support. There was a high success rate with minimal morbidity, similar to findings in an inpatient setting. Patient satisfaction was uniformly high. The author believes that external DCR can be performed on a day-surgery basis safely and successfully.


Histopathologic, immunophenotypic and genotypic analyses in ocular adnexal lymphoproliferative disorders.

This study reports on fourteen biopsies from patients presenting to our orbital and oncology service with ocular adnexal lymphoid proliferations between November 1988 to September 1991. The biopsies were studied using histologic, immunophenotypic and genotypic analyses. By histologic criteria, there were two reactive, five indeterminate and seven lymphomatous lesions. On immunophenotypic analysis, there were two monoclonal and 10 polyclonal lesions in the 12 specimens analysed. Genotypic analysis confirmed the histopathologic diagnoses for the reactive lesions by showing them to be germline. It also confirmed that both the histopathologic lymphomas and immunophenotypically monoclonal lesions were clonally rearranged. Genotypic analysis was able to separate the histologically indeterminate group into two subsets: clonally rearranged, of which there was one, and germline, of which there were four. In addition, it demonstrated that immunophenotypic polyclonality cannot always be equated with genotypic polyclonality as was the situation in four out of 10 lesions in our series. The significance of clonal arrangements in the histologically indeterminate and immunophenotypically polyclonal groups can only be determined by prospective study.


Pseudallescheria boydii keratitis.

We treated a case of post-traumatic keratitis caused by the soil saprophyte, Pseudallescheria boydii. The injury was caused by a wood splinter which produced a perforating corneal laceration that was primarily repaired. Signs of corneal infection were not evident until the fourth postoperative week. The organism was eradicated by topical miconazole and natamycin. Subsequent penetrating keratoplasty combined with cataract extraction and intraocular lens implantation has achieved a good visual outcome.


Atypical mycobacterium keratitis.

We present two cases of Mycobacterium chelonae keratitis, both of which followed minor corneal trauma. One case initially showed improvement with medical therapy alone but eventually required penetrating keratoplasty. The second case required surgical intervention to provide tectonic support, but the infection resolved with antibiotic therapy.


Limbal nodules in Sweet's syndrome.

Sweet's syndrome is acute febrile neutrophilic dermatosis. Conjunctivitis and episceritis have been described with it before. A case of Sweet's syndrome, described here, was found to have limbal nodules with histology similar to the skin lesions. This is the first report of this association.


Diazepam and its effects on visual fields.

A patient who experienced severe visual field loss whilst taking 100 mg of diazepam that reverted to normal on cessation of the drug is described. Diazepam affects GABA inhibitory neurones and the physiology of this in the retina and visual cortex is reviewed.


B and T cell leakiness in the scid mouse mutant.

Recombination of antigen receptor gene elements (V, D and J) that code for Ig and TCR variable regions is defective in the scid mouse mutant. However, the defect is not absolute. Developing scid lymphocytes occasionally succeed in forming a productive VDJ and VJ rearrangement at two critical loci (e.g., IgH/IgL or TCR beta/TCR alpha), and given the appropriate stimuli, differentiate into clones of functional B or T cells. Scid mice with detectable B and/or T lymphocytes are referred to as leaky. This review considers the nature and possible basis of B and T cell leakiness in scid mice.


Domestic animal models of severe combined immunodeficiency: canine X-linked severe combined immunodeficiency and severe combined immunodeficiency in horses.

This review describes the clinical, immunologic and pathologic features of two naturally-occurring models of severe combined immunodeficiency (SCID) in domestic animals that represent different forms of human SCID. Canine X-linked SCID (XSCID) has an X-linked recessive mode of inheritance and, as such, represents a model for the most common form of human SCID in the United States. Affected dogs have normal percentages of circulating B cells and low to normal percentages of phenotypically mature, but nonfunctional T cells. Severe combined immunodeficiency in the horse is an autosomal recessive form of SCID that is characterized by a profound lymphopenia affecting both the B and T cell lineage most likely due to a lymphoid stem cell defect. Since these diseases are naturally-occurring in an outbred species, like man, they represent unique animal models of their respective human counterparts in which to determine the underlying immunologic defect(s), to evaluate novel approaches to immunotherapy or gene therapy, and to evaluate therapeutic regimens for opportunistic infections associated with SCID.


Perinatal HIV transmission facts and controversies.

In 1992, HIV infection in children is essentially due to vertical or perinatal transmission, i.e. from the mother to the fetus and neonates. This is a particularly serious public-health problem in Africa where the percentage of infected women of child bearing age is as high as 20% in some suburban areas. During the last few years, three important points have been established. (i) In Europe and North America, the rate of perinatal transmission is between 15 and 25% and appears to have remained relatively stable with time in various prospective cohorts. (ii) Considerable efforts have been directed at defining the optimal methods for early diagnosis of HIV infection in the infants. At present viral cultures and gene amplification of HIV DNA by polymerase chain reaction are the most promising procedures for early diagnosis within the first 6 months of life. (iii) Finally, the course of the disease in the infected infant has been well characterised, it takes two main forms--that of an early and severe disease or that of a slowly progressive infection: In addition, follow-up is now sufficient to confirm that children with negative tests at 15 months are indeed uninfected. However, knowledge is lacking in a number of essential areas. These include the exact timing of transmission (in utero, during delivery or post-partum), the relative frequency of transmission during each period, the mechanism(s) involved (particularly the role of the placenta), and, finally, the influence of maternal, fetal and viral factors. Answers must be found rapidly in order to develop preventive therapy, to identify women who may have an increased risk of transmitting the virus, to develop a reliable antenatal diagnostic test and, finally, to be in a better position to inform HIV-seropositive women of the relative risks.


Gene therapy for primary immunodeficiency disease.

Gene therapy offers the potential for developing innovative new treatments for both inherited monogenic diseases as well as polygenic and acquired disorders. For most potential clinical applications, the technology has not yet progressed to the stage where it might be reasonably tested. Problems to be solved include the isolation and characterization of the genes involved, the development of gene delivery systems that will permit efficient gene insertion in the affected cells and tissues, and the development of mechanisms to control or appropriately regulate expression of the introduced genes. The primary immunodeficiency diseases as a group actually lend themselves to the development of gene therapy strategies with current technology more readily than almost any other class of disease. Theoretically any genetic disease that can be successfully treated by allogeneic bone marrow transplantation is a potential candidate for gene therapy directed at correcting the patient's own totipotent bone marrow stem cells. In addition, some disorders lend themselves to genetic correction of more mature cells, although gene transfer in this treatment strategy might have to be repeated periodically. The rationale and preliminary results of the first gene therapy protocol for ADA deficiency SCID are described and strategies for developing somatic cell gene therapy for the other primary immunodeficiency diseases are discussed.


Genome exclusion and gametic DAPI-DNA content in the hybridogenetic Bacillus rossius-grandii benazzii complex (Insecta Phasmatodea).

Among Sicilian stick insects, two hybridogenetic complexes have been discovered: Bacillus rossius-grandii benazzii and B. rossius-grandii grandii, which also produce androgenetic offspring. The egg maturation of the former is analyzed here through DAPI fluorometry, which, besides the assessment of the meiotic stages, also allows their DNA measurements and the analysis of sperm-head evolution into male pronuclei in these polyspermic eggs. Hybridogenetic eggs undergo an extrasynthesis of chromosomes, because two groups of n autobivalents (4C each) are segregated at metaphase 1st; the two groups must correspond to the pure parental species haplosets. Then the grandii chromosomes degenerate (1st polar body), while the rossius chromosomes divide further to produce two groups of n autodiads (2C each); one of them degenerates (2nd polar body), and the other is ready to perform syngamy (female pronucleus). Meanwhile, several B. grandii sperm evolve into male pronuclei by doubling their DNA (from 1C to 2C content) and assuming an interphase nucleus appearance. If regular mixis occurs, the F1 hybrid constitution is restored but, if it fails, a fusion between two sperms may occur, originating fully paternal descendants (natural androgenesis). The genome exclusion mechanism of stick-insect hybridogens appears to be more primitive than those observed in the already known hybridogenetic complexes of Poeciliopsis and Rana esculenta. Unfertilized eggs of hybridogens are capable of self-activation, but the cytology of the related clonally reproducing B. whitei indicates that its parthenogenetic mechanism stems from the hybridization event (hybrid theory) rather than from tychoparthenogenetic potentialities (spontaneous theory).


Analysis of the expression of a large number of novel genes isolated from mouse prepubertal testis.

The analysis of genes expressed in a restricted temporal and spatial manner during spermatogenesis has given insights into different gene-regulatory mechanisms active in germ cells. However, very few genes have so far been described that are predominantly active in spermatogonia and the early meiotic cell types of testis. To isolate a battery of such genes, more than 100 different mRNA molecules were isolated from a mouse prepubertal testicular cDNA library, and their expression patterns in different tissues analyzed. Thirty mRNAs, 26 of them previously not described in the literature, were found to be predominantly expressed in mouse testis. A detailed analysis of their expression patterns identified a number of mRNA molecules differentially expressed in testicular cell types, including both germ cells and somatic cell types. Characterization of these mRNAs also revealed five distinct temporal phases of gene expression during prepubertal germ cell development. Three different genes, mainly active in the spermatogonial and the early meiotic cell types of testis, were isolated and will be used to characterize further stage-specific gene expression during germ cell differentiation.


Demonstration of a stage-specific expression of the ZFY protein in fetal mouse testis using anti-peptide antibodies.

The zinc finger Y (Zfy) gene is located on the Y chromosome of all placental mammals. Although it is phylogenetically conserved and is expressed in mouse fetal testis, it is not the sex determining Y (Tdy) gene. To address the possible function of the Zfy gene in mice, the distribution of Zfy protein in fetal mice was investigated by immunocytochemical staining using several specific antisera against synthetic peptides of the mouse Zfy protein. Analysis of various fetal tissues at different embryonic stages demonstrated a specific staining only in fetal testis. In particular, reactive protein was initially observed in male fetal gonads at day 11.5 postcoitum (p.c.). The immuno-staining intensified in fetal testes at day 12 and 12.5 p.c., decreased drastically in those at day 13 and 14 p.c. and became undetectable in those at day 15 p.c. and beyond. The reactive molecules were distributed mostly within the seminiferous tubules of the embryonic testis. The present observations confirm the previous findings with RT-PCR analysis and indicate that Zfy or Zfy-like protein is expressed in stage-specific manner during early testis differentiation. Its location in the seminiferous tubules suggests a possible role in early germ cell development.


Mediation of the actions of insulin and insulin-like growth factor-1 on preimplantation mouse embryos in vitro.

Previous studies showed that both insulin and insulin-like growth factor-1 (IGF-1) stimulate metabolism and growth of preimplantation embryos. Because the effects of insulin occur with very low doses, it was suggested that its effects were mediated by its own receptors. However, the effects of IGF-1 occurred at higher doses, suggestive of cross reaction with the insulin receptor but still in the range for mediation via its own receptor. The aim of this study was to investigate the mediation of the metabolic and growth effects of insulin and IGF-1 using a specific insulin receptor antagonist. The antagonistic B-10 Fab fragment (B-10f) completely blocked stimulation of protein synthesis by both insulin and IGF-1, indicating that the insulin receptor mediates this action of both hormones. Alternately, only insulin's stimulation of inner cell mass mitogenesis and morphological development was inhibited by the B-10 Fab fragment. This showed that growth stimulation by insulin and IGF-1 was mediated via different receptors, insulin through its own receptor and IGF-1 through some other receptor. However, mediation via the IGF-2 receptor is not excluded since IGF-1 stimulates compaction when there is evidence for only the presence of the IGF-2 receptor. In summary, insulin or IGF-1 at physiological concentrations stimulates preimplantation mouse embryos, suggesting an important role for both these growth factors in early development.


Increasing carbon dioxide from five percent to ten percent improves rabbit blastocyst development from cultured zygotes.

One-cell rabbit zygotes were cultured at 39 degrees C in basal synthetic medium II (BSM-II) with 5%, 10%, or 15% CO2 and humidified air to determine the effect of CO2 concentration on development in vitro. After 4 days in culture, 37% of the embryos grown in 10% or 15% CO2 had reached the hatching blastocyst stage, but only 10% of the embryos were hatching when cultured under 5% CO2 (P = 0.01). Over all blastocysts, cell numbers were 207, 246, and 205 for the 5%, 10%, and 15% CO2 treatments, respectively. In a second experiment to determine if there was a beneficial effect, particularly at the blastocyst stage, of a higher concentration of CO2, embryos were cultured 4 days in either 5% or 10% CO2 or for 2 days in 5% CO2 followed by 2 days in 10% CO2. The numbers of blastomeres per embryo and embryo diameter were greater (P < 0.05) in embryos cultured continuously in 10% CO2 or in 10% CO2 only during days 3 and 4 of culture than in embryos cultured continuously in 5% CO2. In a third experiment, one-cell rabbit zygotes were cultured with 5% or 10% CO2 in a defined, protein-free medium consisting of 1:1 RPMI 1640 and Dulbecco's modified Eagle's medium. The proportion of embryos hatching and cell counts were significantly greater (P < 0.01) when cultured in the presence of 10% CO2. These data indicate that a 10% CO2 atmosphere exerts a beneficial effect on the development of zygotes into expanding and hatching rabbit blastocysts in vitro.


In vitro fertilization, development, and implantation after exposure of mature mouse oocytes to visible light.

Mature mouse oocytes were exposed prior to in vitro fertilization to visible light during 1, 2, or 4 hr at an intensity of 4,000 lux. Compared to controls cultured under identical conditions but protected from light, exposed eggs did not show any significant modification of cleavage speed and rate. After transfer of blastocysts obtained in vitro in uteri of pseudopregnant females, the implantation rate and the proportion of normal fetuses were not found to be different in relation to preliminary light exposure of oocytes fertilized and cultured in vitro.


Biosynthesis of prostaglandins by human spermatozoa in vitro and their role in acrosome reaction and fertilization.

Five homogenates of human sperm cells were separately incubated with [14C]arachidonic acid in the presence of reduced glutathione, L-tryptophan, and haematin as cofactors. The cyclooxygenase products of arachidonic acid metabolism were extracted, separated, and measured for their radioactivity. The rate of formation of prostaglandin (PG)D2, PGE2, PGF2 alpha, 6-keto PGF1 alpha, and thromboxane (TX)B2 were 18.0 +/- 1.11, 10.9 +/- 0.68, 5.8 +/- 0.21, 3.9 +/- 0.13 and 6.6 +/- 0.52 pmol/10(6) cells/min, respectively. These results are discussed in relation to the hypothesis that cyclooxygenase metabolites of certain polyunsaturated fatty acids play an important part in the sperm acrosome reaction and fertilization.


Characterization of male meiotic germ cell-specific antigen (Meg 1) by monoclonal antibody TRA 369 in mice.

We have identified a male meiotic germ cell-specific antigen (Meg 1) with monoclonal antibody (mAb) TRA 369 in mice. The Meg 1 antigen was strongly expressed in specific steps of meiotic germ cells from pachytene spermatocyte to early spermatid, and not in other germ cells or somatic cells. Immunohistochemical examination revealed that the antigen was localized to the cytoplasm and was not distributed in the nucleus or on the cell surface. This antigen was demonstrated to have a molecular weight of 93 kDa and an isoelectric point of 5.2 by Western blotting. This molecule was first detected in the testis of 13-day-old mouse when pachytene spermatocytes first appeared. Thus this is a differentiation-specific antigen in male meiotic germ cells, and mAb TRA 369 is a useful tool to study the regulation of germ cell differentiation and to define germ cell development in a molecular level.


Adsorption of oviductal fluid proteins by the bovine sperm membrane during in vitro capacitation.

125I-labeled oviductal fluid (ODF) proteins and antiserum to ODF were used to determine whether ODF proteins associate with the sperm membrane during in vitro capacitation. Luteal and nonluteal pools of ODF were obtained from oviduct catheters during the estrous cycle. Washed sperm (50 x 10(6) sperm/ml) were incubated up to 4 h in a protein-free modified Tyrode's medium (MTM), or MTM supplemented with 40% ODF, or 0.5 ng 125I-labeled ODF proteins. Solubilized sperm membrane proteins and incubation media containing ODF proteins were separated by gel electrophoresis. Membranes isolated from bovine sperm, previously incubated with ODF, adsorbed five 125I-proteins: A doublet at 85-95 kDa, and others at 24, 34, 53, and 66 kDa. The amount of 66 kDA 125I-protein associated with the sperm decreased during the incubation, whereas the amount of 85 to 95-kDa protein did not. Western blot analyses also detected the presence of ODF proteins (53, 66, 85-95, and 116 kDa) in solubilized membranes from sperm incubated in ODF. The 85 to 95-kDa protein in ODF decreased in apparent molecular weight by 5 kDa when associated with the sperm membrane. At 53 kDa, ODF proteins which associated with sperm were transformed from two to three separate proteins. These studies indicate that the surface of sperm is modified by adsorption of ODF proteins to the membrane during in vitro capacitation.


Protein synthesis requirements during resumption of meiosis in the hamster oocyte: early nuclear and microtubule configurations.

The organization of chromatin and cytoplasmic microtubules changes abruptly at M-phase entry in both mitotic and meiotic cell cycles. To determine whether the early nuclear and cytoplasmic events associated with meiotic resumption are dependent on protein synthesis, cumulus-enclosed hamster oocytes were cultured in the presence of 100 micrograms/ml puromycin or cycloheximide for 5 hr. Both control (untreated) and treated oocytes were analyzed by fluorescence microscopy after staining with Hoechst 33258 and tubulin antibodies. Freshly isolated oocytes exhibit prominent nucleoli and diffuse chromatin within the germinal vesicle as well as an interphase network of cytoplasmic microtubules. After 4-4.5 hr in culture, most oocytes were in prometaphase I of meiosis as characterized by a prominent spindle with fully condensed chromosomes and numerous cytoplasmic asters. After 5-5.5 hr in culture, microtubule asters are no longer detected in most cells, and the spindle is the only tubulin-positive structure. Incubation for 5 hr in the presence of inhibitors does not impair germinal vesicle breakdown, chromatin condensation, kinetochore microtubule assembly, or cytoplasmic aster formation in the majority of oocytes examined; however, under these conditions, a population of oocytes retains a germinal vesicle, exhibiting variable degrees of chromatin condensation and cytoplasmic aster formation. Meiotic spindle formation is inhibited in all oocytes. These effects are fully reversible upon culture of treated oocytes in drug-free medium for 5 hr. The data indicate that meiotic spindle assembly is dependent on ongoing protein synthesis in the cumulus-enclosed hamster oocyte; in contrast, chromatin condensation and aster formation are not as sensitive to protein synthesis inhibitors during meiotic resumption.


Determination of enzyme activities of energy metabolism in the maturing rat oocyte.

Enzyme activities were determined quantitatively in individual rat oocytes to study their energy metabolism during maturation. Low hexokinase activity and high activities of lactate dehydrogenase and enzymes in the phosphate pathway, i.e., glucose 6-P and 6-P gluconate dehydrogenases, were characteristic of immature oocytes. Hexokinase may be a rate-limiting enzyme that enables oocytes to use glucose as an energy source. During maturation, the activities of hexokinase, phosphofructokinase, and malate dehydrogenase increased significantly, suggesting that the glycolytic pathway, as well as the tricarboxylic acid cycle, developed as the first meiotic division proceeded. In contrast, the activities of glucose 6-P and 6-P gluconate dehydrogenases decreased in maturing oocytes. The observation that the enzyme pattern in mature oocytes resembles more closely that in somatic cells appears to be significant, especially in light of previous studies showing this developmental trend in preimplantation embryos.


In vitro decondensation of mammalian sperm and subsequent formation of pronuclei-like structures for micromanipulation.

In this study, we describe an efficient protocol for the formation of in vitro developed pronuclei for micromanipulation techniques. Our approach involved incubation of demembranated or permeabilized mammalian sperm in a phosphate buffer supplemented with heparin and beta-mercaptoethanol. Under the prevailing conditions, we achieved a uniform and reliable synchronous decondensation of sperm nuclear DNA. This initial decondensation facilitated the removal of mammalian protamines upon subsequent incubation in an amphibian egg extract. The interchange of protamines for histones to stabilize the DNA structure is recognized as a prerequisite for pronuclear formation. Furthermore, immunocytochemical studies have revealed that pronuclear development is accompanied by the formation of a nuclear lamina with corresponding DNA synthesis. The method described gave a high yield of nuclei during pronuclear formation. Ultimately, our aim is to transfer the in vitro-developed pronuclei into mammalian oocytes by micromanipulation. This novel procedure may prove useful in alleviating severe male factor problems especially in oligozoospermic cases in our in vitro fertilization center.


Parthenogenetic development of bovine oocytes treated with ethanol and cytochalasin B after in vitro maturation.

The present study was conducted to investigate the effects of different culture durations (24-36 hr) on bovine oocyte maturation in vitro and the effect of the presence or absence of cumulus cells at the time of treatment to induce parthenogenetic activation (exposure to ethanol and cytochalasin B; CB) (experiment I). The effects of dosage (2.5 or 5.0 micrograms/ml) and incubation time (2.5, 5, or 10 hr) in CB (experiment II) on the subsequent development to the blastocyst stage in vitro was also investigated. In experiment I, cleavage and development to the blastocyst stage were not affected by the presence or absence of cumulus cells at the time of parthenogenetic activation. However, the 24-hr culture duration for in vitro maturation had a significantly lower rate of development to the blastocyst stage than the longer culture durations (27-36 hr). In experiment II, treatment with 5 micrograms/ml CB for 5 hr showed the highest percentage of development to blastocyst in the oocytes matured for both 27 and 30 hr. To determine the viability of the parthenogenetic embryos (morulae and blastocysts), four recipient heifers received two embryos each, and one heifer was found to be pregnant on day 35 following transfer. Although fetal heartbeat was not observed, the subsequent estrus was prolonged in all heifers. The present results demonstrate development of in vitro-matured, parthenogenetically activated bovine embryos up to the preimplantation stage.


Mucin genes and the proteins they encode: structure, diversity, and regulation.

Mucins are the structural components of the mucus gels that protect the respiratory, gastrointestinal, and reproductive tracts. These polydisperse glycoproteins (250,000 to 20,000,000 D) are approximately 80% carbohydrate on a mass basis and have a high intrinsic viscosity due to their large size and extreme hydrophilicity. Mucin oligosaccharides, the structures responsible for this hydrophilicity, are heterogeneous in size and structure but are chiefly O-linked, i.e., they initiate from N-acetylgalactosamine residues attached to threonine and serine residues of the polypeptide backbone. Our understanding of the structure of mucins has advanced rapidly in the last few years with the isolation and sequencing of cDNA clones that encode mucin polypeptide backbones. All currently well-characterized mucins have been found to contain extended arrays of tandemly repeated peptides rich in potential O-glycosylation sites. Less is known about the unique sequences that flank the tandem repeat arrays of secretory mucins, but currently available information indicates that these flanking regions contain cysteine-rich stretches that participate in mucin oligomer formation. Thus, secretory mucins appear to consist of oligomers containing heavily glycosylated domains flanked by unique sequences required for polymerization. Progress has also been made in characterizing the genes that encode mucins. At least four human mucin genes are known at present, although many others may remain to be discovered. Moreover, much work remains before we gain an understanding of the mechanisms involved in the expression of mucin genes and their tissue-specific regulation.


Ragweed sensitization-induced increase of myosin light chain kinase content in canine airway smooth muscle.

Previous studies have identified changes of mechanical properties of airway smooth muscle (ASM) from a canine model of atopic airway hyperreactivity. These changes, including increased maximum shortening capacity (delta Lmax) and early shortening velocity (Vo), may be responsible for the airway hyperresponsiveness in asthma. We have suggested that these changes may be due to increased actomyosin ATPase activity, controlled via phosphorylation of the 20 kD myosin light chain (MLC20) by MLC kinase (MLCK). Therefore, ATPase activity, MLC20 phosphorylation, and MLCK content and activity were assessed in tracheal and bronchial smooth muscles (TSM and BSM) of ragweed pollen-sensitized dogs (S) and their littermate controls (C). Specific ATPase activities from STSM and SBSM were significantly higher than their control counterparts (CTSM, CBSM). Phosphorylation of MLC20 in STSM was greater both at rest and during electrical stimulation due to the increased amount of MLCK in STSM and SBSM by 30 and 25%, respectively. MLCK activity was also increased significantly in STSM and SBSM (from 46.99 +/- 8.33 and 42.85 +/- 5.92 to 91.9 +/- 6.43 and 64.12 +/- 7.88 32P mmol/mg fresh tissue weight/min respectively [mean +/- SEM]). When normalized to the amount of MLCK in the tissue, however, specific MLCK activity in STSM and SBSM was similar to that in controls. It is unlikely that myosin phosphatase plays any role in the changes of MLC20 phosphorylation in sensitized animals. Peptide mapping showed no visible change in primary structure of MLCK in STSM and SBSM compared with those of controls. We report that ASM actomyosin ATPase activity is increased in STSM and SBSM. The increased ATPase activity is the result of increased MLC20 phosphorylation, the latter likely resulting from the increased MLCK content, which may account for the hyperresponsiveness found in ASM from these animals.


Quantifying proliferation of cultured human and rabbit airway smooth muscle cells in response to serum and platelet-derived growth factor.

Development of suitable methods for the quantification of the proliferative response of airway smooth muscle (ASM) cells in culture will assist the investigation of the cellular mechanisms underlying the hyperplasia and hypertrophy of ASM as seen in asthmatic airways. In this study, two rapid and simple colorimetric assays have been modified to enable the growth of human bronchial and rabbit tracheal smooth muscle in culture to be assessed. One method depends upon the reduction by living cells of the tetrazolium salt MTT to form a blue formazan product, whereas the other relies on rapid binding of the dye Coomassie brilliant blue to protein at acidic pH. Experiments demonstrated the validity of both assays in quantifying the proliferative response of cultured human and rabbit ASM cells. The increase in optical density observed for each assay correlated directly, throughout the duration of culture, with the increase in cell number determined by hemocytometry in human and rabbit ASM cells proliferating in response to fetal calf serum (1.25 to 10%). This relationship held also for rabbit tracheal ASM cells proliferating in response to the heterodimer of platelet-derived growth factor (1 to 50 ng/ml). Application of these methods to adherent proliferating cultures of human and rabbit ASM cells demonstrated their adaptability to the generation of growth curves in response to serum and to a defined growth factor. These methods allow both total cellular protein and proliferation to be estimated in human and rabbit ASM cells in culture, using assays that are rapid, reproducible, inexpensive, and easy to perform while negating the use of radioisotopes. It is intended that these additional methods should be useful in delineating some of the mechanisms that might contribute to the proliferative response of these cells--particularly since there has been a resurgence in interest in culturing smooth muscle cells derived from the airways.


Early maturation of force production in pig tracheal smooth muscle during fetal development.

The contractility of airway smooth muscle is fully established at late term at birth but its responsiveness during fetal life has not been defined. In this study, the contractile force of airway smooth muscle to acetylcholine (ACh), K+ depolarizing solution, and electrical field stimulation (EFS) was measured in tracheas from small fetal pigs. Contraction to either agonist and to EFS was detectable in fetuses of as low as 9 g body weight, which corresponds to approximately 36 days of gestation. Isometric force increased progressively with age, reaching 4.1 +/- 0.4 mN for K+ and 5.8 +/- 0.5 mN for ACh (10(-4) M) at 600 g fetal weight (90 days). However, when normalized for cross sectional area of smooth muscle, the stress was essentially the same from 17- to 600-g fetuses. (K+: 17 g = 74.4 +/- 10.6 mN/mm2, 600 g = 89.3 +/- 13.0 mN/mm2; ACh [10(-4) M]: 17 g = 76.3 +/- 16.0 mN/mm2, 600 g = 127.0 +/- 13.0 mN/mm2). The sensitivities of the various groups to ACh were not significantly different (e.g., EC50: 30 g = 4.0 +/- 0.2 x 10(-6) M, 600 g = 3.7 +/- 1.1 x 10(-6) M). EFS produced frequency-dependent contractile responses in all groups. With increasing fetal size, there was a corresponding increase in force. When this force was normalized to a maximum ACh response (10(-4) M), there was no significant difference between groups of fetuses. Histologic examination showed the major tissue components of the trachea were present in fetuses above 7 g. Immunocytochemistry detected myosin, caldesmon, and filamin in the smooth muscle from fetuses of 7 g and above, showing that contractile and actin-binding proteins were present from a very early age. It is concluded that smooth muscle contractile function is well developed very early in fetal life in pigs.


Secretory proteins and glycoconjugates synthesized by human tracheal gland cells in culture.

To study the proteins and glycoconjugates synthesized by serous cells from human tracheal glands (HTG), isolated HTG cells were cultured in the presence of radiolabeled precursors 14C-proline, Na2(35)SO4, and 3H-fucose. The secretory 14C/35S/3H-radiolabeled proteins and glycoproteins, de novo synthesized by HTG cells, were analyzed by gel filtration chromatography. We observed the incorporation of 14C-proline into antileukoprotease and an unknown 30 kD protein, and the incorporation of 35SO4-- and 3H-fucose into high molecular weight glycoconjugates and sulfoconjugates (M(r) > 1,000,000) and into components with apparent M(r) of approximately 250 and 100 kD. After specific chemical and enzymatic treatment, the 35S- and 3H-glycoconjugates were shown to be -O-linked mucin-like glycoproteins and proteoglycans. These results show that cultured HTG cells synthesize some of the macromolecules identified in bronchial secretions.


The role of the nonciliated bronchiolar epithelial (Clara) cell as the progenitor cell during bronchiolar epithelial differentiation in the perinatal rabbit lung.

Although it is well established that the nonciliated bronchiolar epithelial (Clara) cell serves as the progenitor for itself and ciliated cells in the adult lung following bronchiolar epithelial injury, the nature of this relationship during development has not been well characterized. To define the pattern of proliferation and differentiation of bronchiolar ciliated and nonciliated cells, lungs of fetuses and offspring from time-mated New Zealand White rabbits, ranging in age from 24 days of gestation to 25 wk postnatal (PN), were fixed by airway infusion and embedded for simultaneous light and transmission electron microscopy. Three categories of cells could be distinguished in terminal bronchioles: nonciliated cells with abundant glycogen and variable numbers of organelles; nonciliated cells with little glycogen, large numbers of polyribosomes, and variable numbers of basal bodies; and ciliated cells with cilia of varying height. Together, both types of nonciliated cells were 100% of the epithelium at 24 and 27 days gestation age (DGA). At 30 days DGA, they were 85% of the population; at all postnatal ages, they ranged from 75 to 81% of the total population. Nonciliated cells with polyribosomes and basal bodies were 10 to 20% of the total nonciliated cell population between 24 DGA and 1 wk PN and not found thereafter. Ciliated cells were not observed in animals younger than 30 DGA. Labeling indices of bronchiolar epithelium in fetuses of pregnant rabbits injected with tritiated thymidine, as determined by autoradiography, were 57 cells per thousand at 28 DGA (1 h postinjection [PI]), 76 at 29 DGA (24 h PI), and 114 at 30 DGA (48 h PI).(ABSTRACT TRUNCATED AT 250 WORDS)


Modulation of eosinophil chemotaxis by interleukin-5.

Eosinophilia and eosinophil function are regulated by cytokines such as granulocyte/macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and interleukin-5 (IL-5). We have investigated the modulatory role of IL-5 on N-formyl-methionyl-leucyl-phenylalanine (FMLP), neutrophil-activating factor (NAF/IL-8), platelet factor 4 (PF4), and cytokine-induced chemotaxis of eosinophils from normal individuals. These eosinophils show a small chemotactic response toward PF4 but not to NAF/IL-8 and FMLP. Preincubation of eosinophils with low concentrations of IL-5 caused significantly increased responses toward PF4 and induced a significant chemotactic response toward FMLP and NAF/IL-8. In marked contrast, IL-5 (or IL-3) priming of eosinophils from normal donors resulted in a strong inhibition of GM-CSF-induced chemotaxis. A similar decrease in the chemotactic response toward GM-CSF was observed in eosinophils derived from allergic asthmatic individuals. This finding suggests that the latter eosinophils may have had a prior exposure to IL-5 (or IL-3). Washing of the cells after priming did not abrogate the inhibition of the GM-CSF response. Our data indicate that at low concentrations IL-5 is an important modulator of eosinophil chemotaxis, causing selective upregulation or downregulation of chemotactic responses toward different agents.


Late results (50 to 182 months) of the Jatene operation.

Between May 1975 and August 1991, 184 patients with transposition of the great arteries (TGA) were operated upon by Jatene operation. One hundred and sixteen underwent corrective surgery prior to June 1987 with a follow-up period of between 50 and 182 months. The ages of these 116 patients ranged from 1 day to 84 months (11.53 +/- 15.98). Eleven percent were less than 1 month old, 38% were between 1 and 6 months, 29% between 7 and 12 months and 22% were older than this. Eighty-eight patients (76%) were boys and the weight ranged from 2.4 to 17.0 kg (6.39 +/- 3.38). Thirty-eight patients (20.7%) died in the immediate postoperative period. Of the survivors, 5 died in the late follow-up between 9 and 66 months (endocarditis at 9 and 66 months; gastroenteritis at 20 months; sudden death at 48 months; and during reoperation for relief of pulmonary stenosis (PS) at 60 months). Of the surviving 73 patients, 24 (32.9%) are anatomically normal at a mean period of 92.5 months postoperatively. Twenty-two (30.1%) have dysfunctions without clinical repercussion. Nineteen (26%) have had no recent evaluation and 8 (11%) were submitted to reoperation or angioplasty for relief of PS. Ninety-eight percent of the patients have normal left ventricular function. The majority of the patients surviving 50 to 182 months are in good clinical condition and if dysfunctions are present these show no progression or severe hemodynamic alterations.


Induced hypothermia in the management of refractory low cardiac output states following cardiac surgery in infants and children.

Post-operative low cardiac output states remain a major cause of mortality following cardiac surgery in infants and children. Since 1979 we have used moderate induced whole-body hypothermia in the management of low-output states refractory to conventional modes of therapy. This is based not only upon the relationship between body temperature and oxygen consumption, but also on experimental work showing a beneficial effect of cooling upon myocardial contractility, particularly when there is pre-existing impairment of ventricular function. Between July 1986 and June 1990, 20 children with refractory low-output states were cooled by means of a thermostatically controlled water blanket to a rectal temperature of 32-33 degrees C. The median age was 12 months (1 week-11 years) with a median weight of 6 kg (3.5-33 kg). Ten children survived to leave hospital while a further two made a haemodynamic recovery. There was a marked reduction in heart rate (P < 0.001). The mean arterial pressure rose (P = 0.037) while there was a fall in mean atrial pressure (P < 0.001). There was a significant improvement in the urine output (P = 0.002). A fall in the platelet count (P < 0.001) was not accompanied by any change in the white cell count (P = 0.15). Although it is impossible to say whether cooling influenced the outcome in any of these children, it was usually effective in stabilising their clinical condition. The technique is simple and has a sound theoretical basis.(ABSTRACT TRUNCATED AT 250 WORDS)


Twelve year experience with the modified Blalock-Taussig shunt in neonates.

Between 1978 and 1990, 53 consecutive modified Blalock-Taussig (MBT) shunts were performed on 51 neonates with cyanotic congenital heart disease using 3 mm-5 mm Gore-Tex grafts. Only 4 of these children had uncomplicated tetralogy of Fallot. The remainder had more complicated pathology requiring urgent intervention. Retrospective analysis of the acute and long term results was performed with 100% follow-up, ranging from 1 month to 12 years (mean 3 years). There were 3 (6%) early deaths (within 30 days of operation) and 17 (33%) late deaths. Of the late deaths, 2 died after further palliation, 2 died after total correction and 13 died suddenly at home. Post mortem examination of the 13 sudden deaths revealed blocked shunts in only 3. Actuarial survival at 2 years was 58%. Shunt patency at 12 months was 87% and at 2 years, 62%. No patient used their initial MBT shunt for more than 40 months. Although this shunt provides good initial palliation, there is a high incidence of late sudden death. We are also concerned about the limited life span of the shunt which partly (3/13) explains the sudden deaths. Therefore we have adopted an aggressive approach to re-study by angiography within 3 months of surgery.


The effects of preoperative aspirin therapy on platelet function in cardiac surgery.

Extracorporeal circulation is known to have profound effects upon platelets. Changes in platelet function were assessed in 20 patients undergoing elective coronary artery bypass grafting (CABG) who stopped taking aspirin (100 mg per day) 5-7 days before the operation compared with 20 patients undergoing aortic valve replacement (AVR) who had never taken anticoagulants or aspirin. Platelet aggregometry was carried out using the turbidimetric technique (inducing agents: adenosine diphosphate (ADP) 1.0 and 2.0 mumol/l; collagen 4 micrograms/ml; epinephrine 25 mumol/l), and maximum aggregation as well as the maximum gradient of aggregation were monitored before, during, and after cardiopulmonary bypass (CPB) until the 1st postoperative (p.o.) day. Until the 1st p.o. day blood loss was significantly higher in the CABG (890 +/- 160 ml) than in the AVR patients (420 +/- 120 ml). A total of 8 units of packed red cells (PRC) were given in the CABG group, whereas no homologous blood was necessary in the AVR patients (P < 0.05). The aggregation variables of the CABG patients were lower than in the AVR patients as early as after the induction of anesthesia (difference in maximum aggregation ranged from 13-29%). During CPB and immediately thereafter, all aggregation variables were significantly reduced in the CABG patients (reduction in maximum aggregation ranged from -32 to -49%) and were significantly different from the platelet aggregation in the AVR patients. Five hours after CPB and on the 1st p.o. day platelet aggregation in the CABG group almost returned to baseline values, however, without reaching the values of the AVR patients.(ABSTRACT TRUNCATED AT 250 WORDS)


Quantitation of the turbulent stress distribution downstream of normal, diseased and artificial aortic valves in humans.

Damage to blood corpuscles seems to be related to the magnitude and exposure time of the turbulent shear stresses (TSS). According to in vitro studies the critical TSS level for lethal erythrocyte and thrombocyte damage is 150-400 N/m2, for exposure times within physiological ranges. To study the distribution of TSS in the human ascending aorta, a hot-film anemometer needle probe was used to register blood velocities at 41 evenly distributed measuring points in the cross-sectional area 5-6 cm downstream of the aortic annulus. Measurements were made in the ascending aorta after normal aortic valves (prior to coronary bypass surgery), after stenotic aortic valves, and after implantation of either St. Jude Medical or Starr Edwards Silastic Ball valves. Three-dimensional visualization of velocity profiles were performed and Reynolds normal stresses (RNS) were calculated within 50-ms overlapping time windows in systole. By coordinating the mean RNS for each time window and for all 41 measuring points, 2-dimensional color-coded mapping of the RNS distribution was made. Based on the velocity profiles and the RNS distribution a relative blood damage index (RBDI) was calculated to incorporate the magnitude and exposure time for RNS in the entire cross-sectional area into one parameter. Turbulent shear stresses were estimated by using a previously determined correlation equation between RNS and TSS. After normal aortic valves, RNS was below 4 N/m2.(ABSTRACT TRUNCATED AT 250 WORDS)