Histoplasmosis in Montreal During the Fall of 1963, with Observations on Erythema Multiforme

Although Montreal is in an endemic area, significant clinical histoplasmosis with systemic manifestations has been, until recently, infrequently diagnosed. However, since the autumn of 1963, 31 cases of clinically significant histoplasmosis have been seen by the authors. These were divided into two groups: (1) patients in whom the diagnosis was established on the basis of histological and/or cultural demonstration of the fungus; (2) patients in whom the diagnosis was based on a positive histoplasmin skin test, a complement fixation antibody titre of 1:32 or greater and compatible clinical and radiological findings. An additional group of 11 patients who presented with erythema multiforme was investigated and a heretofore unrecognized relationship between histoplasmosis and erythema multiforme was established.     

Cell function in the ovary of drosophila

Summary The relative DNA content of the ovarian nurse nuclei of Drosophila melanogaster has been measured by high-resolution autoradiography of DNA uniformly labelled with adenine-8-¹⁴C.The various nurse nuclei show a defined pattern of DNA classes. The posterior nuclei, i. e. those nearest to the oocyte, achieve eight reduplications of DNA by stages 8–9, thus reaching 512n, and all have lost some DNA by stage 10. The nuclei in the middle of the chamber achieve seven reduplications of DNA by stage 9, thus reaching 256n, and though there is loss of DNA in the majority of these nuclei at stage 10 some of them might enter a new reduplication cycle. The anterior nuclei, i. e. those more distant from the oocyte, achieve more than seven reduplications by stage 10 and show no loss of DNA.After stage 6 of the ovarian chambers the pattern of DNA enrichment and later degradation is clearly polarized in that there is a posterioranterior gradient for the level of ploidy, the order in time in which this is attained, and the loss of DNA. The dominant end of the gradient is towards the developing oocyte.The measured nuclear volume where DNA is present is well correlated with ploidy till stage 9. Compared with earlier stages, at stage 10 DNA shares less in the nuclear contents than other materials. The nuclear volume when calculated as a sphere is a gross overestimation, except for the earliest stages.Various possibilities likely to bring about differences in the amount of DNA among nurse nuclei within and between chambers are discussed.Research worker of the British Empire Cancer Campaign.     

Effect of the essential oil fromAchillea fragrantissima onEscherichia coli cells

Escherichia coli cells treated with the essential oil from the plantAchillea fragrantissima released five polypeptides as well as K⁺ ions into the incubation medium. The oil also inhibited the respiration ofE. coli cells and reduced their ATP content. Electron micrographs showed that oil-treated cells were permeable to uranyl acetate. The effect of the essential oil on the cell membrane is discussed.     

Poly(fumaric-co-sebacic) microspheres as oral drug delivery systems

The current study focuses on the development of bioadhesive oral delivery systems based on bioerodible polyanhydrides. The polymers were studied and characterized using a novel tensiometer based on a very sensitive electrobalance. The system was designed to mimic in vivo interactions, thus all experiments were conducted with freshly excised tissue immersed in physiological saline at 37 degrees C. Poly(fumaric-co-sebacic) [P(FA:SA)] was found to be the most bioadhesive polymer from a series of different thermoplastic materials evaluated. Correlation with in vivo performance was investigated by determining gastrointestinal (GI) residence time of barium-loaded microspheres. Residence times of 24 to 36 h provided a strong indication that these microspheres were good candidates for bioadhesive drug delivery systems. To evaluate the effect of these materials on bioavailability, the anticoagulant drug, dicumarol, was encapsulated. Systemic blood levels demonstrated increased bioavailability for the encapsulated dicumarol formulation as compared with unencapsulated drug. (c) 1996 John Wiley & Sons, Inc.     

Habitat selection and space use overlap between feral horses,pronghorn, and greater sage-grouse in cold arid steppe

Populations of feral horses (Equus ferus caballus) in the western United States have increased during the past decade, consequently affecting co-occurring wildlife habitat. Feral horses may influence 2 native wildlife species, greater sage-grouse (Centrocercus urophasianus; sage-grouse) and pronghorn (Antilocapra americana) through mechanisms of habitat alteration and competition. Wyoming, USA, contains the largest populations of pronghorn and sage-grouse of any state and also has the highest degree of range overlap between feral horses and these species. Consequently, the effects that horses may have on pronghorn and sage-grouse populations in Wyoming have implications at local, state, and population-wide levels. Managers need information concerning habitat selection and space use overlap among these species to develop appropriate management strategies; yet this information is absent for most feral horse management areas. To address this knowledge need, we attached global positioning system (GPS) transmitters to horses, pronghorn, and sage-grouse within the greater Bureau of Land Management–Adobe Town Herd Management Area in southern Wyoming and northern Colorado, USA, between 2017 and 2021 to evaluate habitat selection and space use of all species during 3 biologically relevant seasons: spring (Apr–Jun; sage-grouse breeding, nesting, and early-brood rearing; pronghorn late gestation and early parturition), summer (Jul–Oct; sage-grouse summer and late-brood rearing; pronghorn late parturition and breeding), and winter (Nov–Mar; non-breeding season). Feral horses selected flatter slopes and shorter mean shrub height across all seasons and were closer to water in spring and summer. Pronghorn habitat selection was similar to horses, but they also avoided oil and gas well pads year-round. During spring, sage-grouse selected greater herbaceous cover, flatter slopes, and areas farther from well pads. In summer, sage-grouse selected greater mean shrub height, flatter slopes, and were closer to water. In winter, sage-grouse selected flatter slopes and areas with greater vegetation production during the preceding summer. Our results indicate strong year-round overlap in space use between horses and pronghorn, whereas overlap between horses and sage-grouse is greatest during the summer in this region. Consequently, managers should recognize the potential for horses to influence habitat quality of pronghorn and sage-grouse in the region.     

Heteropolypeptides from hydrogen cyanide and water? Solid state15N NMR investigations

Cross-polarization magic-angle spinning¹⁵NMR spectra have been used to determine the composition of hydrogen cyanide polymers both before and after treatment with water. The unambiguous presence of secondary amide groups (as in peptide links) has been established by double-cross-polarization studies on the polymers synthesized from equimolar amounts of H¹³CN and HC¹⁵N. The NMR results are consistent with the hypothesis that the original heteropolypeptides on Earth were synthesized directly from hydrogen cyanide and water without the intervening formation of -amino acids.     

Role of thyroid hormone in intermediary metabolism of propranolol or alloxan-treated Calotes versicolor.

Administration of L-thyroxine (T4) to thyroidectomized Calotes versicolor significantly increased the activity of glucose-6-phosphatase (G-6-Pase) (liver and kidney), the concentrations of blood glucose and total protein (liver and kidney), and decreased hepatic cholesterol when compared to thyroidectomized lizards. Propranolol injections in thyroidectomized lizards increased the cholesterol concentration and did not change the other parameters. The activity of G-6-Pase and blood glucose content was stimulated, whereas the total protein and cholesterol contents were decreased after alloxan treatment. Administration of T4 to thyroidectomized animals pretreated with propranolol or alloxan significantly elevated the activity of G-6-Pase, the concentrations of blood glucose, and total protein, and reduced hepatic cholesterol level when compared to drug-treated lizards. From the results, it is evident that thyroid hormone has an independent stimulatory influence on intermediary metabolism in C. versicolor irrespective of the involvement of adrenaline or insulin.     

Lactate dehydrogenase (LDH) activity of the cultured eukaryotic cells as marker of the number of dead cells in the medium [corrected]

One significant problem in monitoring a culture's evolution is to assess change in cell viability. We have demonstrated that LDH release could be a good indicator of cellular damage of many cell lines, especially during shear stress or sonication. Moreover, we have found a significant correlation between the number of dead cells, determined by Trypan Blue staining, and LDH activity measurements in the supernatant of hybridoma strains, whatever the culture conditions. We have also shown that when viability is still near 100% no LDH is released even at high cell concentrations. Therefore, LDH should serve as a potential marker of cell injury and death.     

Well-identifiable human chromosomes Isolated from mitotic fibroblasts by a new method

Summary Metaphase chromosomes isolated from human fibroblasts by lysis of mitotic cells in the presence of the intercalating DNA-specific fluorochrome propidium iodide appear relatively long, even after exposure to vinblastine sulfate overnight. Therefore, they can be easily banded and thereby unequivocally identified. Chromosomes isolated in this way may be employed in flow analysis and sorting without loosing the inducibility of their band patterns.