Ethanol vapours above lacrimal fluid in the rabbit

Ethanol was administered intravenously to rabbits. The concentration of ethanol, determined by gas chromatographic analysis, in lacrimal fluid was shown to reflect the concentration in plasma. The vapour above lacrimal fluid was analyzed in situ by the use of a small resistivity sensor that measures ethanol vapours. After a dose of approximately 750 mg/kg, the metabolic rates of ethanol determined by gas chromatographic analysis of plasma (226 +/- 13 mg.kg-1.h-1) and by eye ethanol vapour analysis (210 +/- 8 mg.kg-1.h-1) were virtually identical. The data suggest that ethanol eye vapour analysis may be an attractive, noninvasive method for the determination of ethanol in animals.     

Immunocytochemical localization of beta-N-acetyl glucosaminidase in human reproductive organs

Immunocytochemical localization of hexosaminidase activity in human males revealed that the enzyme activity is localized mainly in the Sertoli cells and interstitial tissue of the testis and in the columnar cells of the epididymis. In seminal vesicles, activity was observed around the glandular epithelium in the form of fine granules.     

Making sense of the combined effect of interleukin-2 and interleukin-4 on lymphocytes using a mathematical model

The cytokines are the information superhighway of the immune system. They are an important component of the integrated behavior of the system. In order to be able to have a good understanding of the immune system, we must be able to model the effect of cytokines and their combined effect. This work is a step in that direction. We study the combined effect of two cytokines: interleukin-2 (IL-2) and interleukin-4 (IL-4) on some cells of the immune system. Interleukin-2 and interleukin-4 are important growth and differentiation factors for B and T cells. Interleukin-4 antagonizes the effect of interleukin-2 on B cells and some T cells while it synergizes with interleukin-2 on other T cells. We build a mathematical model of the interaction of both cytokines on T and B cells as a building block toward a model of the Th1/Th2 cross-regulation. The response of a given cell to the combination of interleukin-2 and interleukin-4 is shown to involve competing dynamical effects which can lead to either antagnostic or synergistic combined effect. Author to whom correspondence should be addressed at Department of Engineering and Public Policy. Work supported by NIH grant nv: Ai31427.     

Oxidative metabolism and protoplast culture

Summary Barley leaf blade protoplasts accumulate malonaldehyde, a product of lipid peroxidation, during culture. In addition, glutathione levels fall after protoplast isolation and the proportion of glutathione in the oxidized state rises. These data indicate oxidative stress after protoplast isolation and during culture. The cause of this phenomenon is revealed by data showing that the activities of enzymes associated with antioxidative processes including glutathione reductase and ascorbate peroxidase decrease after barley protoplast isolation. In contrast, protoplasts isolated from suspension cultured cells of bromegrass and soybean exhibit little evidence for oxidative stress and increased activities of glutathione reductase and ascorbate peroxidase. We suggest that an antioxidative response is associated with mitosis and colony formation from protoplasts, as exhibited by bromegrass and soybean. Conversely, failure of an antioxidative response is associated with low viability and absence of mitosis, as in barley. Increased viability of barley leaf protoplasts cultured on feeder layer cells is correlated with increased glutathione content and higher glutathione reductase activity.     

Testing the ecological relevance of Daphnia species designations

1. Molecular approaches have increasingly revealed hidden genetic structure within ecologically important species, leading to the creation of sibling species whose ecological relevance is often unclear. A prime example is Daphnia galeata mendotae, which was split into D. dentifera and D. mendotae based on differences at two allozyme loci. 2. In a set of lake populations in Michigan USA, we test the geographical and temporal consistency of the genetic structure underlying this species split. We also test the morphological relevance of this molecular variation and its ecological significance in lakes. In essence, we ask: does recognition of these new species provide valuable information for plankton ecologists? 3. We found that D. dentifera and D. mendotae represent morphologically and ecologically distinct forms that are distributed among lakes in non‐random fashion, which were remarkably stable over 6 years. Key differences between the species concern their body and head shape, vertical habitat use within lakes and distribution among lakes of different size. We hypothesise that these differences represent specialisation to habitats that differ in risk of invertebrate predation. 4. Reproductive barriers alone are insufficient to explain the pattern of genetic structure; in some lakes complete introgression is apparent. However, parent species and hybrids exhibit a stable co‐existence in many lakes, which suggests that ecological specialisation reinforces divergence within this taxon.     

Identification,cloning, and sequencing of DNA essential for encapsulation of Streptococcus pneumoniae

This paper reports the cloning and sequencing of a region of DNA from Streptococcus pneumoniae serotype 3 surrounding transposon Tn916, insertion of which was previously shown to result in lack of expression of the extracellular capsule. Sequence analysis revealed that the transposon inserted into a consensus insertion site 71 bp from the 5 end of the cloned fragment. Within the clone, 3 downstream regions from two different pneumococcal lytA genes were identified, as well as a putative 194 AA open reading frame (ORF1). Moreover, two copies of the repeat element BOX, oriented in opposite directions, were located immediately 3 of orf1. Within the region bounded by the first pair of internal sequencing primers, analysis revealed that the fragment amplified by PCR was always of the same size. Moreover, Southern blotting showed that for all serotypes examined to date, homology exists with the cloned fragment. These results indicate that this region of the chromosome is highly conserved and, taken together with other independently derived data, suggest that interruptions or deletions within this DNA lead to unencapsulation.     

Nitrate assimilation in Crotalaria juncea (Linn.) pollen suspension culture

In vivo and in vitro activities of nitrate reductase were assayedin Crotalaria juncea pollen suspension cultures. This enzymewas found to be substrate-inducible and enhanced activity wasobserved when it was extracted with cysteine buffer or incubatedwith NADH (0.6 mM) at 25?C or when the germinated pollen grainswere treated with red light for 10 min. Enzymes of ammonia assimilation,glutamate dehydrogenase and glutamate synthetase, and also thepentose phosphate-shunt enzyme, glucose-6-phosphate dehydrogenase,which catalyzes the step that provides reducing power to thesystem, are described. (Received October 20, 1977; )     

Serum and semen levels of immunoreactive prolactin, LH and FSH in normospermic, oligospermic and azoospermic men with obstructive infertility prior to and after vasoepididymostomy.

Attempts were made to validate RIA for prolactin (PRL), LH and FSH in semen from normospermic, oligospermic and azoospermic subjects. The RIA used to measure PRL and LH in semen fulfilled the criteria of reliability, whereas low levels of FSH in semen precluded the validation of FSH assay in semen. Semen levels of PRL and LH were significantly (P < 0.05) higher than serum levels in all groups of subjects investigated. Semen levels of FSH in azoospermic men after vasoepididymostomy (VEA), were significantly (P < 0.05) higher compared to azoospermic men prior to surgery. Serum levels of PRL were significantly higher (P < 0.05) in normospermic men compared to oligospermic and azoospermic men prior to and after surgery. Semen levels of PRL in normospermic men were comparable with oligospermic and azoospermic subjects prior to and after surgery. Serum levels of LH in oligospermic and azoospermic men who did not undergo surgery and in men reporting oligospermia after VEA were comparable to normospermic subjects but in men showing azoospermia post surgically, serum LH levels were significantly (P < 0.005) elevated. Semen levels of LH in men reporting azoospermia before surgery and in subjects showing oligospermia or azoospermia post surgically were significantly lower (P < 0.05) compared to men with normal sperm count. Serum levels of FSH were significantly elevated (P < 0.05) compared to semen levels in oligospermic men prior to surgery but this increase was not seen in post VEA subjects. These results were discussed.     

Some neuronal cell populations express human dopamine beta-hydroxylase-lacZ transgenes transiently during embryonic development.

The 5' flanking region from the human dopamine beta-hydroxylase gene directs expression of bacterial beta-galactosidase reporter genes to a subset of adult neurons and adrenal chromaffin cells of transgenic mice. In this paper, we examine the spatial and temporal patterns of expression of these transgenes during embryogenesis. Expression begins at embryonic day 9 in the developing central and peripheral nervous systems and persists in cell populations in which expression is observed in adult transgenic mice. However, transient embryonic expression occurs in presumptive neuroblasts in developing sensory ganglia and ventrolateral neural tube that are destined to synthesize neurotransmitters other than catecholamines. These observations support the concept that some cells fated to become "non-catecholaminergic" neurons exhibit transient catecholaminergic features during their differentiation.