Structure-dependent induction of CYP2B by polychlorinated biphenyl congeners in female Sprague-Dawley rats

The dose-response induction of hepatic microsomal pentoxyresorufin O-dealkylase (PROD) activity by phenobarbital (PB) and several polychlorinated biphenyl (PCB) mixtures and congeners was determined in the immature female Sprague-Dawley rat. At a dose of 75 mg/kg/day of PB for 3 days, the microsomal PROD activity was 2154 pmol/min/mg protein. Aroclors 1260, 1254, 1242, and 1016 did not induce maximal PROD activity at doses up to 500 mg/kg, and only Aroclor 1016 induced > a half-maximal response at the 500 mg/kg dose. The relative potencies of eighteen different PCB congeners were also determined, and the structures of these compounds differed with respect to the degree of chlorination (tri- to octochloro) and substitution patterns. The relative potencies of these compounds were estimated by comparing their induced activities at the high dose (150 or 100 mg/kg) with that of PB. The most potent inducers were 2,3,3',4',5,6-hexaCB and 2,2',3,4',5,5',6-heptaCB; at a dose of 150 mg/kg, the PROD activity induced by 2,2'3,4',5,5',6-heptaCB was comparable to that observed for PB. 2,3,3',4',5,6-HexaCB was the most potent inducer, and hepatic PROD activity in rats treated with 150 mg/kg was 4202 pmol/min/mg; this value was higher than that observed for PB at a dose of 75 mg/kg. A second group of congeners including 2,2',3,4,4',5,5'-heptaCB, 2,2',4,4',5,5'-hexaCB, 2,2',3,3',4,4',5,5'-octaCB 2,2',4,4'-tetraCB, 2,2',4,5,5'-pentaCB, 2,2',3,4,4',5',6-heptaCB, 2,2',4,4',5-pentaCB and 2,2',3,3',4',5,5',6-octaCB induced PROD activity > or = 1090 pmol/min/mg at the 150 mg/kg dose, and this value was > 50% of the maximal response observed for PB. The remaining compounds, namely 2,4,4'-triCB, 2,2',3,4'-tetraCB, 2,2',5,5'-tetraCB, 2,3',4,4',5-pentaCB, 2,3,3',4,4'-pentaCB, 2,2',4,4',5,6'-hexaCB, 2,3,3',4,4',5,5'-heptaCB and 2,2',3,3',4,4,5-heptaCB were all relatively weak inducers of hepatic microsomal PROD activity ( < 450 pmol/min/mg). In parallel experiments, western blot analysis of immunoreactive CYP2B1 and CYP2B2 protein showed that PB, the PCB mixtures, and congeners induced both proteins. Previous studies have identified a cis-acting DNA element that plays a role in regulating CYP2B1/B2 gene expression and binds nuclear trans-acting factor(s) induced by PB. The results of gel electrophoretic mobility shift assays with nuclear extracts showed that both PB and 2,2',3,4',5,5',6-heptaCB induce formation of a common retarded band using a 32P-labeled oligonucleotide corresponding the the cis-acting DNA promoter sequence. Both PB and PCBs appear to induce CYP2B1/B2 via a common mechanism. Although the results of this study do not define structure-induction (CYP2B1/B2) relationships for PCBs, two compounds, namely 2,3,3',4',5,6-hexaCB and 2,2',3,4',5,5',6-heptaCB, were identified as highly potent inducers.

Interlaboratory reproducibility of yeast protein patterns analyzed by immobilized pH gradient two-dimensional gel electrophoresis

An interlaboratory comparison was conducted on the positional and quantitative reproducibility of yeast proteins resolved by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) using isoelectric focusing with immobilized pH gradient (pH 4-7) in the first dimension. The basic experimental set-up was as follows: one laboratory prepared and distributed a [35S]methionine-labeled total yeast protein extract (Göteborg, Sweden), another laboratory prepared the IPG strips to be used by all labs in this study (Munich, Germany), the third laboratory (Aarhus, Denmark) circulated the protocols and coordinated the modest attempts to unify them. Samples were run horizontally in the first dimension and vertically in the second. The gels were sent to Göteborg for processing by phosphoimager technology and computerized image analysis (PDQuest), and the 2-D PAGE resolved proteins were located and quantified automatically. A subset of 470 spots was manually matched in all gels out of an average of 1328 resolved proteins. The positional interlaboratory comparison revealed great pattern reproducibility, the correlation coefficient in no case being less than 0.9994. In absolute terms an average deviation of 2.8 mm (x-position) and 1.8 mm (y-position) were obtained for all nine gels (three gels per lab). The interlaboratory comparison of protein quantitation displayed higher variability, and the best correlation coefficient generated was 0.975. An average standard deviation of 34.5% was calculated for protein quantitation including all three labs, a value slightly higher than the intralaboratory variation (range 20-28%). Thus, despite differences in protocols, chemicals and equipment, the immobilized pH gradient technology gave extremely high positional and quantitative reproducibility. This will greatly facilitate the exchange of data and the establishment of multi-user image-based 2-D gel databases.

Purification of a novel protein (ps20) from urogenital sinus mesenchymal cells with growth inhibitory properties in vitro

Our previous studies have characterized mesenchyme-derived proteins to identify biologically active proteins and novel markers for stromal cell paracrine action relative to stromal-epithelial interactions. Previous reports have characterized properties of a growth inhibitory activity (to bladder and prostatic epithelial cells), secreted by U4F fetal rat urogenital sinus mesenchymal cells, not cross-reactive with antibodies to known cytokines, and provisionally termed UGIF. The present study reports the characterization, purification, and biological properties of a 20-21-kDa protein responsible for UGIF activity. The 20-21-kDa protein (termed ps20) was purified to near homogeneity, the amino-terminal sequence was determined, and biological properties were characterized in vitro. Amino-terminal sequence analysis indicated no direct matches or regions of homology with known proteins. Purified ps20 induced a linear and saturable inhibition of [3H]thymidine incorporation in PC-3 prostatic carcinoma cells (half-maximal activity at 2.6 nM), inhibited cell proliferation (increased population doubling time from 19.8 to 25.8 h), and induced a 210% stimulation in the synthesis of secreted proteins. These data suggest that ps20 may be a candidate paracrine effector protein and may play a role in stromal-epithelial cell interaction in the prostate gland.

[Nasal myiasis]

Thirty fly maggots were retrieved from the nasal cavity of a 23-year old man who had one week previously received treatment for a nasal fracture. The larvae were identified as Calliphora erythrocephala. These are not a common cause of myiasis as they normally breed on carrion. In myiasis it is important to establish whether the larvae are invasive or not. A brief description of nasal myiasis is given.

Beta-2 microglobulin is mitogenic to PC-3 prostatic carcinoma cells and antagonistic to transforming growth factor beta 1 action

Previous studies have identified a M(r) 12,000 protein in rat prostatic stromal cell-conditioned medium with growth stimulatory activity to human prostatic carcinoma cells as a direct match with beta 2-microglobulin (beta 2-m). The present study was conducted to characterize the activities of human beta 2-m directly, using commercially available, purified human beta 2-m. Beta 2-m was assayed for growth stimulatory activity to human PC-3 prostatic carcinoma cells and rat PS-1 prostatic stromal cells and for antagonistic activity to transforming growth factor beta 1 (TGF-beta 1)-induced growth inhibitory actions. Beta 2-m acted to stimulate [3H]thymidine incorporation in PC-3 cells in a linear, concentration-dependent and saturable manner in serum-free medium. Beta 2-m stimulated cell proliferation and significantly decreased population doubling times in both PC-3 and PS-1 cell lines. At half-maximal concentrations of TGF-beta 1 and lower, beta 2-m acted in a concentration-dependent, antagonistic manner, acting to stimulate growth-inhibited PC-3 cells to fully neutralize TGF-B1 activity. In contrast, cells exposed to maximum activity TGF-beta 1 concentrations were refractory to beta 2-m action, regardless of the concentration tested. This represents the first report to demonstrate a growth-stimulatory activity of B2-m with carcinoma/epithelial cells and to show beta 2-m antagonistic activity to TGF-B1 growth-induced inhibition. Beta 2-m has been shown previously to associate with hormone/growth factor receptors. Together, these data suggest that beta 2-m may play a role in modulating cell proliferation, possibly through modification of ligand/receptor kinetics. Owing to the elevation of both beta 2-m and TGF-beta 1 in many dysplastic-neoplastic conditions, beta 2-m may be relevant to mechanisms of abnormal proliferation disorders and in modulating TGF-beta 1 mechanisms of actions.

Prevention of clinical trichostrongylidosis in calves by strategic feeding with the predacious fungus Duddingtonia flagrans

The present investigation showed that strategic feeding of first-season calves with the microfungus Duddingtonia flagrans through the initial 3 months of the grazing season could prevent severe clinical trichostrongylidosis in the late summer. The successful prevention of disease was particularly noteworthy in view of the high stocking rate practiced on this permanent pasture, which was widely contaminated with a range of gastrointestinal nematodes. The results showed that larval populations of Ostertagia and Cooperia were significantly reduced on the pasture grazed by the fungus-treated calves. Numbers of Nematodirus seemed less affected. The present paper discusses the complexity of fungus-nematode interactions in dung pats under natural conditions.

Volatile anaesthetics: cellular mechanisms of action

The mechanisms by which volatile anaesthetics act in the central nervous system are reviewed. The main cellular targets are excitatory synapses and the cell membrane of the neuronal cell body/dendrite, although there also appears to be a significant effect on thin unmyelinated fibres. Experiments quantifying these effects have shown that 1 MAC isoflurane reduces the activity in afferent fibres by 18%, excitatory synapses by 27% and postsynaptic neurones by 24%. Two important effects observed when recording from individual neurones are hyperpolarization of the cell membrane by an enhanced potassium conductance and increased threshold for initiation of action potentials. Excitatory synaptic transmission is most probably reduced due to a decreased release of transmitter from presynaptic terminals. Antagonistic and biphasic effects are often seen, for instance depression of both inhibitory and excitatory transmission and depolarization-hyperpolarization of the postsynaptic membrane.

Photochemical bleaching of fluorescent glycosylation products

We have examined the effect of visible light and ultraviolet on the non-enzymatic glycosylation of lysine in vitro. Glucose and L-lysine were mixed and incubated under white light, UV-A, UV-B, or in the dark. During 15 days of incubation in the dark, a heterogeneous mixture of intensely brown chromophores developed, with a dominant fluorescence excitation maximum at 350 nm and emission maxima near 425 nm. The process was delayed or inhibited to a moderate extent by white light, whereas under UV-A and UV-B this effect was more pronounced. We conclude that non-enzymatic glycosylation can be photochemically modulated by both visible light and ultraviolet.

Probenecid inhibition of the outward transport of fluorescein across the human blood-retina barrier

The effect of probenecid on the outward transport of fluorescein from vitreous to blood was studied in 13 insulin-dependent diabetic patients with background retinopathy in a randomised double-masked placebo controlled cross-over study. Fluorescein and fluorescein glucuronide was separated in the vitreous and in plasma by differential spectrofluorometry. The data for fluorescein were analysed using a simplified mathematical model of the eye. The inward permeability was estimated from data obtained 1 h after injection and the outward transport from data obtained 7 h after injection. During placebo treatment the mean inward permeability was 3.75 x 10(-7) cm/sec and the mean outward permeability was 2.25 x 10(-5) cm/sec. During probenecid treatment the mean inward permeability was 3.34 x 10(-7) cm/sec and the mean outward permeability was 1.44 x 10(-5) cm/sec. Thus, we found no significant change in inward permeability (p = 0.5879), whereas a significant decrease of 36% was found in the outward permeability of fluorescein (p = 0.0171). The demonstration that the outward permeability, which is more than 100-fold higher than the inward permeability in the healthy eye, is significantly decreased by probenecid, demonstrates that active transport is involved in movement of fluorescein across the blood-retina barrier from the vitreous to the plasma.

Fluorescein transport across the human blood-retina barrier in the direction vitreous to blood. Quantitative assessment in vivo

Inward and outward movement of flourescein across the human blood-retina barrier was studied in five healthy volunteers, using a differential spectrofluorometry method that eliminates the contribution of fluorescein glucuronide to the total fluorescence in the vitreous and in plasma. The inward permeability across the blood-retina barrier, which is presumed to be passive, and the diffusion coefficient in the vitreous for fluorescein was calculated from data obtained 1 h after intravenous injection of fluorescein. The rate of elimination of fluorescein from the vitreous across the blood-retina barrier was estimated from data obtained 7 to 12 h after injection of fluorescein. The calculations were based upon the free plasma fluorescein decay curve and the preretinal fluorescein gradient in the vitreous. The mean inward permeability of fluorescein was 1.39 x 10(-7) cm/sec (range: 0.70-2.06 x 10(-7) cm/sec), whereas the mean outward permeability was 1.51 x 10(-5) cm/sec (range: 1.14-1.73 x 10(-5) cm/sec). We have thus found that the movement of fluorescein across the blood-retina barrier is highly asymmetric, the outward transport being more than 100 times faster than the passive inward leakage. This could indicate the presence of an active pumping mechanism in the blood-retina barrier, responsible for fluorescein transport in the direction from the vitreous to the blood.

The effect of the volatile anesthetic isoflurane on Ca(2+)-dependent glutamate release from rat cerebral cortex

A major effect of volatile anesthetics is to reduce excitatory synaptic transmission. In the present study the stimulated release of glutamate under the influence of increasing concentrations of isoflurane was studied in vitro by utilizing hippocampal slices from Wistar rats. Ca(2+)-dependent release was calculated by subtracting stimulated release with blocked synaptic transmission (50 mM K+, 0 mM Ca2+ and 4 mM Mg2+) from total evoked release (50 mM K+, 2 mM Ca2+ and 1 mM Mg2+). Isoflurane 0.5, 1.5 and 3% reduced Ca(2+)-dependent release of glutamate to 69, 58 and 49%, respectively (P < 0.05 for all related to control). These results are in agreement with the possibility of reduced release of transmitter as a mechanism of action of volatile anesthetics.

Evaluation of canines for accelerant detection at fire scenes

In recent years, canines have been successfully used in fire investigations to detect accelerant residues. We set out to determine the lower limits at which canines could reliably detect potential accelerants. Measured amounts ranging from 10 to as little as 0.01 microL of gasoline, kerosene, and isopars were applied to preselected spots along a continuous sample path (25 to 40 feet long) made out of burned and unburned wood or nylon carpeting strips at the testing site. Two canines were led past this sample path at least three times and positive alerts and negative responses were recorded. Both dogs were generally able to alert on spots containing 0.01 microL or more of all three accelerants, at or beyond the purge and trap recovery and gas chromatographic detection method employed. The canines did alert occasionally on background, especially that containing traces of styrene residues, either purposely added in specific amounts or formed upon partial pyrolysis of carpeting material. The dogs alerted on sites containing 0.1 to 1.0 microL of freshly applied gasoline or kerosene placed at actual heavily damaged fire scenes, but were less successful on samples containing smaller amounts.

A novel approach to express a heterologous gene on Kluyveromyces lactis linear killer plasmids: expression of the bacterial aph gene from a cytoplasmic promoter fragment without in-phase fusion to the plasmid open reading frame

Using the cytoplasmically localized killer plasmids pGKL1 and pGKL2 of Kluyveromyces lactis a new linear hybrid plasmid (pWKL1) was constructed. It consists of pGKL1 into which, in addition to the previously developed cytoplasmically expressible LEU2* selection marker, a phosphotransferase encoding bacterial antibiotic resistance gene has been integrated. In the hybrid plasmid pWKL1 this gene was preceded by a putative transcriptional signal from pGKL2, i.e., the upstream conserved sequence of ORF5 (UCS5). All foreign genes, so far integrated and expressed in linear plasmids, required in addition to a cytoplasmic promoter (UCS) an in phase fusion to the corresponding open reading frame. In this study the UCS5, not containing the translational start of ORF5, and the aph coding region were intentionally not combined in phase, in order to check whether expression can occur under these conditions. Kluyveromyces lactis transformants carrying pWKL1 were highly resistant against the antibiotic geneticine (G418) and exhibited elevated levels of APH activity. Expression of the aph gene was due to the presence of the UCS5 containing fragment (110 bp). Thus, an in phase fusion was not required for expression. This is the first report that, concomitant with a selectable marker gene, foreign DNA can be integrated in a linear plasmid via homologous recombination and more importantly, that in phase fusions are not required generally for expression of heterologous genes in linear plasmids.

Absence of foveal avascular zone demonstrated by laser scanning fluorescein angiography

We present laser scanning fluorescein angiograms of abnormal foveal capillary patterns in a healthy subject and an insulin-dependent diabetic patient with mild diabetic retinopathy. In both subjects capillaries were seen to cross the central foveal area where capillaries are usually absent. The flow pattern of the foveal capillaries, which were visualised with the use of a laser scanning ophthalmoscope, was indistinguishable from that of the more peripheral capillaries, indicating that foveal vessels are functionally normal retinal capillaries. The two cases demonstrate that identification of abnormal capillary patterns induced by retinal disease such as diabetic retinopathy is made difficult by the marked interindividual variation in capillary anatomy. In prospective studies, however, the method may be capable of detecting subtle changes in early diabetic retinopathy with a high degree of sensitivity.

Early changes in diabetic retinopathy: capillary loss and blood-retina barrier permeability in relation to metabolic control

In diabetic retinopathy capillary loss and blood-retina barrier leakage are prominent factors. We present a study with quantitative measurements of both capillary loss and leakage and their relation to cumulative metabolic control. Seventeen insulin-dependent diabetic patients with no retinopathy or only mild background retinopathy and 10 years' duration of the disease were included in the study. Status of metabolic regulation had been followed for at least 6 years. Seven healthy subjects were included as controls. In diabetic patients the perifoveal intervascular areas were found to increase significantly with the cumulative HbA1c index (p = 0.02) and in relation to the presence of moderate background retinopathy (p < 0.02). The blood-retina barrier leakage and the area of the foveal avascular zone were not significantly different from healthy subjects and no correlation was found between the HbA1c index and blood-retina barrier permeability. We conclude that perifoveal capillary loss occurs early in the course of diabetic retinopathy and that this loss is related to prior glycemic control and to the ophthalmoscopic retinopathy level.

Chloroflexus-like organisms from marine and hypersaline environments: Distribution and diversity

We report the presence of a diverse number ofChloroflexus-like organisms in intertidal marine and submerged hypersaline microbial mats using light, infrared fluorescence, and electron microscopy. The intertidal organisms appear morphologically very similar to thermophilicC. aurantiacus while the 2 hypersaline strains are larger and have a more complex ultrastructure composed of chlorosome-bearing internal membranes that appear to arise as invaginations of the cell membrane. By comparing spectroradiometry of microbial mat layers with microscopic observations, we have confirmed that theChloroflexus-like organisms are major constituents of the hypersaline microbial mat communities. In situ studies on mat layers dominated byChloroflexus-like organisms showed that sulfide-dependent photoautotrophic activity sustained by near infrared radiation prevailed. Autoradiographic analyses revealed that autotrophy was sustained in the filaments by 750 nm radiation. Three morphologically distinct strains are now maintained in mixed culture. One of these appears to be growing photoautotrophically.

The potential of nematophagous fungi to control the free-living stages of nematode parasites of sheep: survey for the presence of fungi in fresh faeces of grazing livestock in Australia

In the course of 12 months, 1742 fresh faecal samples from grazing livestock, principally ruminants, from various States of Australia were examined for the presence of nematophagous fungi. In total, 48 separate isolations were made representing various species from the genus Arthrobotrys and also 16 isolates of the single Duddingtonia species, Duddingtonia flagrans. These isolates will be used in continuing studies to select the most suitable species, on the basis of nematophagous capability and ruminant gut survival capacity, for development of a biological means of controlling nematode parasites of livestock.

An attempt to implement the nematode-trapping fungus Duddingtonia flagrans in biological control of trichostrongyle infections of first year grazing calves

An attempt was made to control Ostertagia ostertagi by feeding the nematode-trapping fungus Duddingtonia flagrans (DSM 6703) to grazing calves. One group of calves (group E) was fed the fungal material in the first two months of the grazing season while another group was a non-treated control group (group C). Group E showed significantly lower faecal egg count in August and September. On four occasions in July and September, the herbage larval counts were significantly lower on the plot with the fungal-treated group than those recorded on the control plot. The average abomasal larval and adult worm counts were significantly reduced in August in group E and the average total worm count in the abomasum of group E was reduced by 87% in August compared to the non-treated group C. In October, the difference in average abomasal worm counts between group E and C was insignificant. Due to weight loss at the end of the grazing season, the control group showed a significantly lower average weight increase.

The potential of nematophagous fungi to control the free-living stages of nematode parasites of sheep: in vitro and in vivo studies

Following in vitro screening investigations on approximately 100 nematophagous fungi reported previously, eight species were selected for further investigation. Fungal elements (mycelium and conidia) were subjected to in vitro stress selection designed to simulate rumen and abomasal conditions. From these studies, three species, namely, Arthrobotrys oligospora, Arthrobotrys oviformis and Geniculifera eudermata, were selected for in vivo survival studies in sheep surgically fitted with abomasal and ileal cannulae. Doses of fungal conidia were administered orally or via the abomasal cannulae and samples of digesta were taken from the abomasum, the terminal ileum and faeces. The viability of the three fungal species at these sites was demonstrated. The abundance of fungi throughout the gut was dose-dependent but in all cases only very small volumes of fungal suspension containing unprotected conidia were used. These results demonstrate that a practical means of orally administering nematophagous fungi to control free-living stages of nematodes in faeces may become an achievable objective.

Asian affinities and continental radiation of the four founding Native American mtDNAs

The mtDNA variation of 321 individuals from 17 Native American populations was examined by high-resolution restriction endonuclease analysis. All mtDNAs were amplified from a variety of sources by using PCR. The mtDNA of a subset of 38 of these individuals was also analyzed by D-loop sequencing. The resulting data were combined with previous mtDNA data from five other Native American tribes, as well as with data from a variety of Asian populations, and were used to deduce the phylogenetic relationships between mtDNAs and to estimate sequence divergences. This analysis revealed the presence of four haplotype groups (haplogroups A, B, C, and D) in the Amerind, but only one haplogroup (A) in the Na-Dene, and confirmed the independent origins of the Amerinds and the Na-Dene. Further, each haplogroup appeared to have been founded by a single mtDNA haplotype, a result which is consistent with a hypothesized founder effect. Most of the variation within haplogroups was tribal specific, that is, it occurred as tribal private polymorphisms. These observations suggest that the process of tribalization began early in the history of the Amerinds, with relatively little intertribal genetic exchange occurring subsequently. The sequencing of 341 nucleotides in the mtDNA D-loop revealed that the D-loop sequence variation correlated strongly with the four haplogroups defined by restriction analysis, and it indicated that the D-loop variation, like the haplotype variation, arose predominantly after the migration of the ancestral Amerinds across the Bering land bridge.

The role of nematophagous fungi in the biological control of nematode parasites of livestock

The control of nematode parasites of livestock is presently based entirely on anthelmintic treatment and grazing management. On their own, these methods are not sustainable because parasites invariably develop resistance to anthelmintics and because of increasing public concern about chemical residues in livestock products and the environment. Although alternative, non-chemotherapeutic control strategies, such as vaccines and genetic selection for resistance are the focus of considerable research activity worldwide, biological control of nematode parasites has been virtually ignored. The little work that has been done is restricted largely to western Europe and involves virtually just one fungal species, namely Arthrobotrys oligospora. More recent studies indicate other known nematophagous fungal species are more efficient predators of infective larvae in sheep faeces than A. oligospora, and others have a greater capacity to survive passage through the gastrointestinal tract of ruminants. These findings plus the relatively sparse numbers of microbial competitors in the fresh faecal environment, compared with the plant rhizosphere where biological control of plant parasites is proving a particularly intractable problem, engenders optimism that the biological control of animal parasitic nematodes may become a practical reality. Such control will never be a substitute for chemotherapy, where the primary purpose is worm removal from the host, but should be incorporated together with other options into integrated pest management systems to provide sustainable nematode control of livestock into the twenty-first century.

Biological control of nematode parasites in cattle with nematode-trapping fungi: a survey of Danish studies

In Denmark two series of experiments have been performed to study the interactions between larvae of bovine gastrointestinal nematode parasites and nematode-trapping fungi. For practical reasons we were interested in the possibility of depositing nematode-trapping fungi in cattle faeces after passage through the gastrointestinal tract. In the first series, laboratory tests with the fungus Arthrobotrys oligospora showed that motile free-living larvae of a wide range of animal-parasitic nematodes and some soil-living nematodes effectively induce the formation of traps. Larvae of all parasitic nematodes are rapidly captured in these traps. The induction of nets was influenced by temperature, number of larvae, atmosphere, light, and media composition. Captured first- and second-stage larvae were quickly penetrated and killed while third stage larvae were killed slowly, perhaps because they are partially protected by an outer dead sheath. Laboratory and field studies showed that when A. oligospora material was directly mixed into dung a significant reduction in the number of infective parasite larvae in the dung and surrounding herbage occurs. This reduction was also reflected in the acquired worm burden of calves grazing on fungal treated pasture. However, the A. oligospora strain studied in the above mentioned experiments did not survive passage through the alimentary tract of cattle. This prompted us to start a second series of experiments to isolate fungi that could survive gut passage of cattle. Different soil and compost samples were screened by an in vitro stress selection technique. This simulated certain important stress factors which occur during passage through the alimentary tract of ruminants. Rumen exposure was found to be a major limiting factor, but some Arthrobotrys and Duddingtonia strains survived submersion in rumen fluid. In a subsequent in vivo experiment, some of these survivors were fed to calves, and it was hereby demonstrated that isolates of both genera, i.e. Arthrobotrys and Duddingtonia, were able to survive passage through calves and significantly reduce the number of developing preparasitic larvae in dung of fungal treated calves. In a controlled field experiment, isolates of Duddingtonia reduced the level of infective third-stage larvae in herbage by 74-85%.

Biological control of Ostertagia ostertagi by feeding selected nematode-trapping fungi to calves

Three nematode-trapping fungi, one Arthrobotrys oligospora and two Duddingtonia flagrans isolates, were fed to Ostertagia ostertagi-infected calves to test their ability to destroy larvae of this parasite in faeces and consequently to reduce the transmission of infective larvae to herbage. The fungi had previously been selected for their capability to pass the alimentary tract of cattle without losing growth and nematode-trapping potentials. Dung was collected from three calves each fed one of the three fungi and placed as 1-kg cow pats on a parasite-free grass plot together with control cow pats from a calf that was not given fungi. The cow pats contained comparable concentrations of parasite eggs. The two D. flagrans isolates were highly effective in that they reduced herbage larval infectivity by 74-85%. In contrast, A. oligospora did not show any effect in the present experiment. Field experiments will demonstrate if D. flagrans represents a potential organism for biological control of bovine gastrointestinal nematodes under practical agricultural management conditions.

Development of immunity to Ostertagia ostertagi (Trichostrongylidae: Nematoda) in pastured young cattle

This experiment comprised 3 groups of calves, (+P2), (-P2) and (-P1), which all started their first grazing season as parasite-free calves. The (+P2)- and (-P2)-group grazed 2 seasons. In the first season the (-P2)-group of calves was grazing a pasture with no detectable trichostrongyles and treated with anthelmintics every second week. The untreated (+P2)-group grazed an Ostertagia ostertagi contaminated pasture. During the second grazing season these 2 original groups grazed together with a new group of first-year grazing calves (-P1) on paddocks infected with O. ostertagi. Parasitological analyses showed that (+P2)-group had negligible egg excretions in the second year in comparison with (-P2) and (-P1). This indicated, that the egg output may be regulated through acquired immunity. The difference in egg excretions was not reflected in the serum pepsinogen levels, which were only slightly elevated for all groups in the second year. Post mortem examination at the end of the experiment showed that only the (-P1)-group harboured relatively high numbers of worms in the abomasa at that time. Antibodies of 3 immunoglobulin classes were investigated: IgA, IgG1 and IgG2. The IgA and IgG1 responses correlated with the presence of developing and adult worms in the abomasa and they remained elevated in the (+P2)-group throughout the experiment, perhaps indicating an involvement of these antibodies in a protective immune response. In the (-P2)-group the IgA and IgG1 showed fast and sharp rises during the second season that most likely were age-related and as such a result of maturation of the immune system. The role of IgG2 is unclear as the IgG2 response was weak in all groups of calves and difficult to relate to the parasitological data.

Interferon alpha-2a treatment of patients with subfoveal neovascular macular degeneration. A pilot investigation

It has recently been suggested that interferon alpha-2a has a beneficial effect on exudative age-related macular degeneration (AMD). So far, results are controversial, and masked, placebo controlled, randomized studies with well-defined inclusion criteria are required to assess the effect of interferon alpha-2a. In preparation for such a study we performed a pilot investigation that included 5 patients with subfoveal neovascularizations. All patients received interferon alpha-2a (Roferon-A, Hoffmann La-Roche) 1.5 mio, IU subcutaneously every second day for 8 weeks. Improved visual acuity was subjectively observed by 4 patients and objectively by 3 patients. Two patients showed decreased central visual field defect. Fluorescein angiography and fundus photography showed ambiguous changes. Amsler chart and contrast sensitivity also showed heterogenous results. Even though the treatment with interferon alpha-2a may show some positive effect, our results are not unequivocal and serve to underline the need for controlled studies before the effect of interferon alpha-2a on neovascular AMD can be reliably assessed.

Ocular fluorometry methodological improvements and clinical studies--with special reference to the blood-retina barrier permeability to fluorescein and fluorescein glucuronide

The measurement of fluorescence in the human eye can be made using relatively simple instruments. Fluorescence is evoked when illumination is absorbed by intrinsic fluorophores in the eye or by artificially introduced extrinsic fluorophores. Intrinsic fluorescence is evidence of important molecular characteristics of the ocular tissues, whereas the extrinsic fluorophores are used primarily in the study of the barriers between the anatomical and physiological compartments of the eye. Blood-retina barrier leakage of fluorescein can be examined after the intravenous injection of fluorescein by quantitative determination of fluorescence in plasma and in the vitreous. From these measurements of the distribution of fluorescein, the permeability of a hypothetical spherical interface between the blood and the retina can be estimated using a mathematical model of the barrier. The use of fluorescein as a tracer is problematic because of its rapid metabolic conversion to fluorescein glucuronide. This metabolite disturbs ocular fluorescence measurements because it fluoresces over the same part of the spectrum as the parent compound. Additionally, the glucuronide occurs in markedly different concentrations depending upon the patient's renal function. With the previously used fluorometry techniques it has been impossible to determine the contribution of fluorescein glucuronide to the vitreous fluorescence. The primary objective of the studies described in this thesis was to develop a method for the determination of fluorescein and fluorescein glucuronide in the human eye and in plasma, and to calculate the blood-retina barrier permeabilities of the two substances. The necessary methodological improvements included a detailed description of the geometrical optics of the eye and the optical filter properties of the lens. A new method was developed for the determination of the spatial locations of ocular fluorescence measurements and the intrinsic lens fluorescence was used to estimate lens transmittance. The new techniques were applied to clinical studies in patients with diabetic retinopathy. It was shown that in insulin-dependent diabetes mellitus, the apparent rate whereby fluorophores are accumulated in the lens is increased in inverse proportion to the quality of metabolic control, i.e. patients who have had consistently poor control have higher fluorescence than patients who have been in good control. An increase in lens fluorescence was also found in the presence of diabetic nephropathy. The results support the assumption that lens fluorometry can provide a rough estimate of cumulative glycaemia and that glucose is involved in certain age-related changes in the lens.(ABSTRACT TRUNCATED AT 400 WORDS)

[Physical causes of accidental falls among the elderly in their own homes]

Accidental falls in elderly persons involve considerable illness and great hospital costs. During the period 1971-1986, the incidence has risen from 14 to 19 per 1000 annually. Four hundred and seventy-three individuals aged 60 years or more who had fallen in their own homes and who sought help in Odense Hospital after the accident were interviewed consecutively. The replies to these interviews described the circumstances involved in the fall together with the health and social conditions. Women constituted 78% of the material with preponderance of people living alone as compared with the background population. Just under half of the patients had had a previous fall. Fractures were sustained in 40% of the cases. In 51% of the cases, a definite or probable external circumstance was the cause of the fall. In 150 out of 237 accidental falls, caused by external circumstances, the accident was considered to have been preventable by means of eg more accessible lighting, non-slip carpeting, removal of doorsteps, more suitable arrangement of furniture and better supportive measures beside stairs. The risk of falling is found to increase markedly in persons aged 75 years or more. Prophylactic measures are recommended before patients reach this age by means of information to elderly persons and to persons involved in home care about situations involving risks.

HIV infection at outcome of pregnancy in the Paris area, France

The prevalence of HIV infection in women at end of pregnancy, irrespective of outcome, was determined in a comprehensive survey of both women and medical centres during successive 4-week periods in four areas of the Paris region, France. Blood samples were tested anonymously for antibodies to human immunodeficiency virus (HIV)-1 and HIV-2. Of the 11,593 blood samples 0.40% (95% confidence interval [CI] 0.28-0.51) were positive for HIV-1 and 0.02% (95% binomial interval [BI] 0.002-0.065) for HIV-2. Seroprevalence was higher among women with ectopic pregnancy (2%) (95% BI 0.24-7.04); the rate in women having an elective or therapeutic abortion was more than twice that in those delivering babies (0.70% vs 0.28%, p less than 0.05, relative risk 2.54, 95% CI 1.36-4.75). Studies with neonatal HIV seroprevalence as a surrogate for HIV prevalence in pregnant women would underestimate prevalence in these women.

In vivo passage through calves of nematophagous fungi selected for biocontrol of parasitic nematodes

The experiment was designed to test the survival and performance of stress selected nematophagous fungi after passage through the gastro-intestinal tract of cattle. Ruminating calves were fed daily with a fixed amount of fungal material grown on barley grains. The excreted dung was collected on days four and five after the start of the feeding experiment. Barley grains were washed out of the excreted dung and incoculated on water-agar plates. After incubation for one week, nine of ten fungal isolates were re-isolated from these plates. The predatory capacity of the fungi in the excreted faeces was tested in a dung pat bioassay and a faecal culture system. In the dung pat bioassay, two fungi of the genus Arthrobotrys and six of the genus Duddingtonia reduced the development of Ostertagia ostertagi third stage larvae by 85% (61%-93%), compared to the number of larvae developed from fungus-free control pats. In seven out of these eight isolates, the reduction of larvae in the faecal cultures was 92% (76%-99%).

Development of immunity to Ostertagia ostertagi (Trichostrongylidae: Nematoda) in pastured young cattle

This experiment comprised 3 groups of calves, (+P2), (-P2) and (-P1), which all started their first grazing season as parasite-free calves. The (+P2)- and (-P2)-group grazed 2 seasons. In the first season the (-P2)-group of calves was grazing a pasture with no detectable trichostrongyles and treated with anthelmintics every second week. The untreated (+P2)-group grazed an Ostertagia ostertagi contaminated pasture. During the second grazing season these 2 original groups grazed together with a new group of first-year grazing calves (-P1) on paddocks infected with O. ostertagi. Parasitological analyses showed that (+P2)-group had negligible egg excretions in the second year in comparison with (-P2) and (-P1). This indicated, that the egg output may be regulated through acquired immunity. The difference in egg excretions was not reflected in the serum pepsinogen levels, which were only slightly elevated for all groups in the second year. Post mortem examination at the end of the experiment showed that only the (-P1)-group harboured relatively high numbers of worms in the abomasa at that time. Antibodies of 3 immunoglobulin classes were investigated: IgA, IgG1 and IgG2. The IgA and IgG1 responses correlated with the presence of developing and adult worms in the abomasa and they remained elevated in the (+P2)-group throughout the experiment, perhaps indicating an involvement of these antibodies in a protective immune response. In the (-P2)-group the IgA and IgG1 showed fast and sharp rises during the second season that most likely were age-related and as such a result of maturation of the immune system. The role of IgG2 is unclear as the IgG2 response was weak in all groups of calves and difficult to relate to the parasitological data.

Lens fluorescence in relation to nephropathy in insulin-dependent diabetes mellitus

The relationship between diabetic nephropathy and blue-green lens fluorescence, lens transmittance, and other lens fluorometry parameters was studied in patients with long-term insulin-dependent diabetes mellitus. The findings in 10 patients who presented with diabetic nephropathy were compared with those of 11 patients of comparable age and duration of diabetes but without nephropathy. Diabetic nephropathy was associated with increased lens fluorescence (P = 0.04) and decreased lens transmittance (P = 0.045). We propose that lens changes may be responsible for various psychophysical abnormalities in diabetic patients and that our results explain the correlation of these abnormalities with the degree of microangiopathy.

Long-term results of extracapsular cataract extraction with posterior chamber lens implantation: sodium hyaluronate 1% vs hydroxypropyl methylcellulose 2%

We investigated the frequency of surgical complications and the long-term outcome in terms of visual acuity, intraocular pressure and post-operative complications in 206 extracapsular cataract extraction procedures with posterior chamber lens implantation using either sodium hyaluronate 1% (Healon) or hydroxypropyl-methylcellulose 2% over a follow-up period of 12 months. We found no significant difference in the results of using either of the two viscoelastic agents.

Ability of the fungus Pleurotus pulmonarius to immobilise preparasitic nematode larvae

In vitro experiments showed that the oyster mushroom Pleurotus pulmonarius exerts a strong immobilising effect on preinfective larvae of the animal parasitic nematodes Ostertagia ostertagi, Cooperia oncophora, Oesophagostomum quadrispinulatum and Cyathostoma species. Infective stages of the same species seemed less vulnerable to fungal attack, possibly because they are protected by their outer cuticle.

Blood-retina barrier permeability in diabetes during acute ACE-inhibition

We assessed the acute effect of ACE-inhibition (captopril) on blood-retina barrier (BRB) permeability in 10 hypertensive insulin-dependent diabetic patients with background retinopathy in a double-masked placebo controlled cross-over study. All patients underwent ophthalmological examination, fundus photography, fluorescein angiography, vitreous fluorometry, and continuous blood pressure recording within 3 h of the drug/placebo administration. The decrease in mean arterial blood pressure, from placebo treatment 149/92 +/- 17/7 to captopril treatment 132/83 +/- 14/7 mmHg (mean +/- SD), P less than 0.01 was not accompanied by a significant decrease in BRB permeability, which was 2.51 (1.24-9.15) with placebo and 3.02 (1.25-13.93).10(-7) cm/s during captopril treatment (geometric mean and-range), NS. Our study suggests that abnormal leakage through the BRB in hypertensive insulin-dependent diabetic patients with background retinopathy is caused predominantly by structural changes in the retinal vessels whereas hydrostatic forces play a minor role.

In vitro stress selection of nematophagous fungi for biocontrol of parasitic nematodes in ruminants

Laboratory experiments were designed to select nematophagous fungi that were able to survive in vitro conditions simulating passage through the gastro-intestinal tract of cattle. All of the tests were conducted at 39 degrees C. In a primary stress selection step in diluted rumen fluid, 21 isolates were obtained. Each of the primary stress selected isolates was tested in synthetic saliva, rumen fluid simulating the activity in the rumen, rumen fluid followed by pepsin-hydrochloric acid treatment simulating the additional effect of ruminal and abomasal activity, pepsin-hydrochloric acid solution simulating conditions in the abomasum and finally in a trypsin solution as an example of enzyme activity in the gut. The effect of the rumen fluid alone, or rumen fluid followed by pepsin-hydrochloric acid treatment, were responsible for the reduction in surviving fungal isolates. Only six of thirteen isolates belonging to the genus Arthrobotrys survived while seven of eight isolates of the genus Duddingtonia survived. Fourteen isolates were tested for their predatory capacity in a dung pat bioassay. Fungi of the genera Arthrobotrys and Duddingtonia reduced the development of Ostertagia ostertagi third stage larvae by approximately 75% and 96% respectively compared to the number of larvae that developed from fungus-free control pats.

[Infrared tympanic thermography. A comparison of body temperature measured rectally and from the tympanic membrane]

Infrared tympanic thermography is a new method of measuring body temperature. We compared body temperature measured in the rectum and in the ear in 25 patients. The results reveal a difference of average +/- 0.3 degree C. We also measured the time used to perform the above procedures. We found that the preparation and completion procedures took on average two minutes and 50 seconds when the body temperature was measured in the rectum. Taking the temperature in the ear took on average 42 seconds. We found that this new method was an accurate and quick method to measure body temperature.

Differential spectrofluorometry in the human vitreous: blood-retina barrier permeability to fluorescein and fluorescein glucuronide

A method is described for the separate quantitation of fluorescein and fluorescein glucuronide in the vitreous by differential spectrofluorometry. An ocular fluorometer was equipped with monochromatic laser excitation at two rapidly interchangeable wavelengths. The data analysis accounts for absorption of light in the cornea, lens, and extrinsic ocular fluorophores. Examination of seven patients with insulin-dependent diabetes and different degrees of diabetic retinopathy demonstrated that both fluorescein and fluorescein glucuronide enter the eye through the blood-retina barrier. The mean ratio between the permeabilities of fluorescein glucuronide and fluorescein was 0.9 (range, 0.3-1.9). Thus, differences in the molecular size and lipid solubility of the two substances appear to be of little or no importance for their inward penetration of the barrier. No association was found between the relative permeability and the degree of retinopathy.

Determination of spatial coordinates in ocular fluorometry

A method has been developed for the determination of spatial coordinates of ocular fluorescence measurements made by a non-contact-lens type of fluorometer (Fluorotron, Coherent Inc., Palo Alto, Calif., USA). The method is based upon a mathematical model of the instrument and the eye. The model is adapted to the individual eye by the extraction of information from the fluorescence scan and the use of keratometry to determine the radius of curvature of the anterior corneal surface. The validity of the model was examined by comparison of the ocular axial length as measured by fluorometry vs ultrasonometry in 26 eyes of healthy human subjects. The results of fluorometry differed from those of ultrasonometry by less than +/- 2%.

Lens fluorometry: light-attenuation effects and estimation of total lens transmittance

Front-face fluorometry of the axial fluorescence profile of the lens is influenced by attenuation of light along the optical pathways leading to and from the detection volume. The resulting distortion is evident when the curve is compared with the intrinsic profile that can be recorded by direct measurement on the transected lens. Assuming that attenuation of light by scatter and absorption is proportional to fluorescence, the intrinsic profile can be reconstructed from the non-invasive fluorescence profile. The calculations involve the deduction of total lens transmittance and fluorescence-related absorptivity, parameters that provide essential information about the optical quality of the lens. The method was applied to human lens fluorometry in vivo and in vitro (excitation 430-490 nm, fluorescence 530-630 nm). Even the most anterior lens fluorescence measurements were found to be markedly affected by attenuation of light in the lens. Lens transmittance estimates agreed within +/- 12% with direct measurements of lens transmittance. The differences were due in part to inter-individual variations in the shape of the intrinsic fluorescence profile of the lens.

[Prevention of perinatal hepatitis B virus transmission. Epidemiology and cost/efficacy ratio in the Paris region]

The HBs antigen (AgHBs) was detected in 152 out of 6605 (2.3 percent) pregnant women who attended four representative maternity clinics in the Paris region. In 98 percent of the cases this finding reflected chronic hepatitis B virus infection. Among women born outside France (47 percent of the women tested, 79 percent of the AgHBs positive women), the relative risk was 6 for Asiatics, 5.5 for Africans and 4 for French women born in overseas departments or territories. Whatever the women's geographical origin, studies of their medical history revealed no significant difference between AgHBs positivity and AgHBs negativity. Overcrowding and multiparity correlated globally with the presence of AgHBs, but this correlation was absent in French women born in France. In non-African and non-Asiatic women detection guided by medical and socio-familial criteria would not be efficacious. The authors recommend systematic detection of AgHBs in pregnant women and estimate at about 180,000 french francs the cost of prevention for each case evolving toward the vital complications of chronic hepatitis B virus infection, an outcome which in the long term may affect 600 individuals born each year and who had contracted the infection during the perinatal period.

[Perinatal transmission of the hepatitis B virus in Paris region]

HBsAg was detected in 152 pregnant women among 6,605 (2.3%) screened in the prenatal clinics of four hospitals representative of the Paris metropolitan area. In 98% of cases, HBsAg positivity indicated chronic HBV carrier status. Among patients born out of continental France (47% of screened women, 79% of positive women) relative risk of chronic infection was 6 in Asians, 5.5 in Africans, and 4 in French women born in non-continental France. No significant difference in medical history was seen between HBsAg-positive and HBsAg-negative patients, in any of the birthplace groups. In women born out of continental France, number of children and crowding of the home were correlated with HBsAg-positivity; these correlations were not found in French women born in continental France. In non-African, non-Asian women, screening on the basis of medical, social and familial criteria (simulated in this study) would not be effective. Routine screening for HBsAg in pregnancy is advocated. The cost of the prevention of each case of perinatally acquired chronic HBV infection by routine screening followed by prophylactic treatment of at risk neonates was estimated at 180,000 French Francs (35,000 dollars). This approach is the only means of preventing the long-term life-threatening complications of chronic HBV infection in the 600 neonates born each year in France to HBsAg-positive mothers.

Longterm remission of multiple brain metastases with tamoxifen

A case of multiple brain metastases from breast carcinoma treated with tamoxifen is described. She remained in remission for 58 months and is still alive after 82+ months of hormone therapy. The case indicates that hormonal treatment may be very effective in the management of brain metastases from breast carcinoma.