[Intra-orbital space occupying lesion. Differential diagnostic considerations based on a rare case]. / Intraorbitale Raumforderung. Differentialdiagnostische Uberlegungen anhand eines seltenen Falles.

The differential diagnosis of an intraorbital tumor is discussed on the basis of a rare case of cyst formation that presented clinically in the lacrimal duct. Rapid progression of exophthalmos and visual loss required an immediate surgical intervention. Using a medial orbitotomy, a cystic tumor was extirpated that had no connection to the paranasal sinuses. Postoperatively, the visual defect and exophthalmos resolved completely. This case demonstrates the problems of differential diagnosis within the orbit that require close interdisciplinary cooperation. The final diagnosis can often be made only after surgical exploration and histopathology of tissue specimens.

[Preliminary studies of the content of lead, cadmium and arsenic in feed, cattle and food of animal origin from different production regions of Saxony]. / Erste Untersuchungen zur Belastung von Futtermitteln, Rindern und Lebensmitteln tierischer Herkunft aus unterschiedlichen Produktionsgebieten Sachsens mit Blei, Kadmium und Arsen.

The modern industrial and agricultural production provides many contact points for the food animals with several toxic substances. After their ingestion by the way of feed or water they may endanger the human health as residues or environmental contaminants in food of animal origin. Currently meat, milk and eggs produced on farms in the new federal states of Germany are considered to be dangerous with respect to their xenobiotic burden by numerous consumers. The own trials have been made to give first information about lead, cadmium and arsenic concentrations in feedstuffs, meat and milk from different dairy farms in Saxonia. No serious problems could be detected referring to the metal contents in roughage, grain and crops. Only a few feed samples reached eg. exceeded the permissible upper limits for arsenic and cadmium. But none of the examined feedstuffs contained inadmissible lead concentration. Milk and muscle produced in a metal polluted and not polluted areas were very low in cadmium, lead and arsenic. Total different is the situation in the cases of liver and kidney. Both organs of cows held on farms near a smelter were rich in cadmium and lead. The cadmium concentration in liver and kidney often and the lead concentration sometimes exceeded the permissible upper limits for food. In this context cadmium in kidney of older cows seems to be a problem in general. The results of the own examinations give no information about differences in the mean metal burden of feed and food between new and old federal states of Germany.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy of various treatment regimens, using liposomal streptomycin in cows with brucellosis.

Thirty cows naturally infected with Brucella abortus were treated by various routes, using free or liposomal streptomycin or a combination of liposomal streptomycin and a long-acting oxytetracycline preparation. Of 21 cows treated with liposomal streptomycin alone, 3 (14%) were culture negative and 3 had 10 or fewer bacterial colonies isolated from tissues obtained at necropsy. Thirteen (62%) cows continued to shed organisms in udder secretions and were considered treatment failures. Of 9 cows that were given a combination of liposomal streptomycin and long-acting oxytetracycline, 5 (56%) were cured, 3 had 10 or fewer colonies on culture plates of tissue after necropsy and only 1 continued to shed B abortus in udder secretions after treatment. Eleven cows were given streptomycin liposomes by intramammary infusion with or without IM administration of long-acting oxytetracycline. The most effective regimen consisted of 2 intramammary infusions of streptomycin liposomes and 2 doses of oxytetracycline administered IM. Of 5 cows treated thusly, 2 were cured and all others had fewer than 10 B abortus colonies isolated from tissues obtained at necropsy.

Interaction of electrically charged drug molecules with phospholipid membranes.

Model membranes (egg-yolk PC liposomes) were exposed to the cationic form of amphiphilic drugs. Microelectrophoresis was used to measure the change of the electrokinetic potential as a function of the drug concentration. By use of the Gouy-Chapman theory the surface potential and surface charge density were calculated. A theoretical model postulating a simple partition equilibrium of the charged drug molecules between the membrane and the aqueous phase in the vicinity of the membrane failed to describe the experimental results. Modification of the partition law by introducing a mechanism of saturation at high drug concentrations, however, resulted in concordance of model and experiment. Some parameters of the model can be used as a means of evaluating the efficiency of neuroactive drugs.

Treatment of Brucella canis and Brucella abortus in vitro and in vivo by stable plurilamellar vesicle-encapsulated aminoglycosides.

Stable plurilamellar vesicles (SPLVs) entrapping aminoglycosides were used to treat infections due to Brucella species (Brucella canis and Brucella abortus). SPLV-entrapped antibiotics effectively eliminated internalized B. canis in cultures of resident murine peritoneal macrophages and internalized B. abortus in cultures of resident guinea pig peritoneal macrophages. In vivo studies demonstrated that SPLV-entrapped aminoglycosides administered to B. canis-infected mice and B. abortus-infected guinea pigs effectively eliminated bacteria from infected organs. The dosage schedule used involved two intraperitoneal administrations of SPLV-entrapped aminoglycosides at three-day intervals. The results demonstrate the superiority of SPLV-entrapped aminoglycosides to free aminoglycosides in effecting elimination of facultative intracellular bacteria in vitro and in vivo. The use of SPLVs as a drug carrier has broad application to treatment of infections due to other organisms.

Liposome-collagen gel matrix: a novel sustained drug delivery system.

This report describes the properties of a novel sustained-release drug delivery system comprising liposomes sequestered in a collagen gel. Two peptide hormones, insulin and growth hormone encapsulated in vesicles sequestered within the matrix, are slowly released into the circulation from either an intramuscular or subcutaneous injection site. A maximum 3-5-d release for insulin or a 14-d growth hormone release was observed. Enhanced sequestration of liposomes with the collagen can be achieved by modifying the liposome surface with fibronectin. The liposome gel delivery system appears to offer several advantages over other liposome formulations or gel formulations constructed only with free drug.

Novel multilayered lipid vesicles: comparison of physical characteristics of multilamellar liposomes and stable plurilamellar vesicles.

The preparation of a new kind of multilayered liposome, called a stable plurilamellar vesicle (SPLV), is described. Although SPLVs and classical multilamellar vesicles (MLVs) are made of the same materials and appear overtly similar in the electron microscope, the two types of vesicles differ as determined by stability, entrapment efficiency, electron spin resonance (ESR), NMR, X-ray diffraction, and biological effects. It is demonstrated that, contrary to what has been assumed, classical MLVs exclude solutes during their formation and, thus, are under a state of osmotic compression. By contrast, the SPLV process produces liposomes that are not compressed. The effects of osmotic compression are discussed. It is suggested that the state of osmotic stress is an important variable that distinguishes various types of liposomes and that has significant physical and biological consequences.

Enhanced graphic matrix analysis of nucleic acid and protein sequences.

The enhanced graphic matrix procedure analyzes nucleic acid and amino acid sequences for features of possible biological interest and reveals the spatial patterns of such features. When a sequence is compared to itself the technique shows regions of self-complementarity, direct repeats, and palindromic subsequences. Comparison of two different sequences, exemplified by immunoglobulin kappa light chain genes, by using colored graphic matrices showed domains of similarity, regions of divergence, and features explainable by transpositions. Analysis of mouse constant domain immunoglobulin sequences revealed self-complementary regions that can be used to fold the molecule into a structure consistent with electron microscopic observations. Computer translation of nucleic acid sequences into all possible amino acid sequences followed by graphic matrix analysis provides a way to detect the most likely protein encoding regions and can predict the correct reading frames in sequences in which splicing patterns are not defined. Application of this technique to regions of simian virus 40 and polyoma virus demonstrates the frames of translation and shows the agreement of sequences determined in separate laboratories with different virus isolates. The graphic matrix technique can also be used to assemble fragmentary sequences during determination, to display local variations in base composition, to detect distant evolutionary relationships, and to display intragenic variation in rates of evolution.

The cytoskeletal framework and poliovirus metabolism.

The cytoskeletal framework prepared by detergent lysis of suspension-grown HeLa cells is compared to the structure obtained from poliovirus-infected cells. This framework, which retains major features of cell morphology and carries the cellular polyribosomes as well as the major structural filaments, is profoundly reorganized following virus infection. This reorganization underlies, at least in part, the morphological changes termed the "cytoplasmic effect." These cytoskeletal changes appear related to the involvement of the framework with viral-specific metabolism. Extensive cytoskeleton alterations occur even when guanidine inhibits viral replication, and thus result from small amounts of early viral products. The normally spheroidal nucleus deforms, allowing a modified region of the cytoplasm to occupy a central position in the cell, and many membrane-enclosed vesicles peculiar to the infected cell are elaborated here. The skeleton preparation reveals that this region contains intermediate filaments arranged in a pattern unique to infected cells. Further changes occur when viral replication is permitted. The central region filaments become coated with darkly staining material which may be viral RNA. Numerous small particles appear on the filaments which resemble partially assembled virions. Mature virions, however, have no affinity for the cytoskeleton and appear to be free in the cytoplasm. Host cell messenger RNA, normally attached to the skeletal framework, is released in infected cells and is replaced by the viral-specific polyribosomes. The trabecular network which carries polyribosomes appears to be rearranged; the viral polyribosomes are located principally at the cell periphery and are excluded from the central region. The viral replication complex with its double-stranded RNA is also attached to the skeletal framework and may comprise the dark staining material coating the filaments of the central cell region.

Messenger RNA abundance and lifetime: a correlation in Drosophila cells but not in HeLa.

Messenger RNA in eukaryotes is comprised of several abundance classes. Also, the decay of these unstable molecules shows at least two very different lifetimes. Two independent techniques are used here to examine the relation between message abundance and lifetime in cell lines from very different organisms. The methods give consistent results for each cell line; however, the two cell types show very different results. In brosophile cells, slowly decaying sequences fall in the abundant class while scarce sequences turn over rapidly. In contrast, in HeLa cells the abundant and scarce message classes are each comprised of long- and short-lived molecules.

Schizophrenic cognitive dysfunction: a deficit in rule transfer.

This study examined conceptual rule learning (RL) deficit in male schizophrenic Ss categorized into three groups as defined by Whitaker Index of Schizophrenic Thinking (WIST). Ss were administered a conjunctive, disjunctive, conditional or biconditional rule learning task, WIST, and Shipley-Hartford Memory Scale. It was shown that: (a) the WIST reliably differentiates among three levels of thought disorder as reflected by a deficit in inter-problem transfer of rule learning; (b) certain WIST and Shipley parameters reliably predict RL performance; and (c) phenothiazine dosage levels show no influence on the WIST and no correlation with RL. The findings indicate that cognitive dysfunction in schizophrenics is evidenced by limited inductive reasoning, insufficient channel capacity for filtering out irrelevant information, and inability to gain from antecedent RL experience. Principal locus of schizophrenic thought disorder is examined within a stimulus encoding-information processing paradigm.

A cytoskeletal structure with associated polyribosomes obtained from HeLa cells.

A method is described by which HeLa cells can be fractionated to reveal a skeletal-like structure in the cytoplasm. This cytoskeleton has many of the cell's ultrastructural features, such as 100A filaments, microfilaments, centrioles, and microspikes, although most of the cellular protein, membranes, and microtubules have been extracted. Associated with the cytoskeleton are most of the polysomal, but not the monomeric, ribosomes. These polysomes are distributed throughout the cytoskeleton except in the region of the 100A filaments, which resembles the distribution in intact cells. Degradation of mRNA with low levels of ribonuclease releases most ribosomes from the cytoskeleton. Prior disaggregation of polyribosomes in vivo releases ribosomes but not mRNA. Cytochalasin B administered in vivo releases the mRNA from the cytoskeleton. These results suggest an attachment of polyribosomes to the cytoskeleton via mRNA.