Injection-seeded alexandrite ring laser: performance and application in a water-vapor differential absorption lidar

A new laser system for use of differential absorption lidar (DIAL) in measurements of tropospheric water vapor and temperature is introduced. This system operates in the 720-780-nm region and is configured as an alexandrite ring laser injection seeded by a cw Ti:sapphire ring laser. This combination provides for the necessary narrow-bandwidth, high-frequency stability and excellent spectral purity. A bandwidth of <5.0 x 10(-3) cm(-1), a frequency stability of 2.1 x 10(-3) cm(-1) rms, and a spectral purity of 99.995% at 726 nm have been achieved during extended periods of operation. A comparison of a DIAL water-vapor measurement with a radiosonde in the boundary layer between 500 and 2000 m was performed. The maximum deviation between the humidity profiles is 15%, the standard deviation 1.6%, and the difference between the mean values 1%.

A new approach to determining homopolymer domain sizes in polycarbonate-polyether dialysis membranes by solid-state NMR

The size of micro-separated domains of polyether (PEO), -[CH2CH2O]n-, and polycarbonate (PC), -[(C6H4)-C(CH3)2-(C6H4)-OCO2]m-, in the dialysis membrane 'Gambrane' have been determined using an advanced solid-state NMR technique which exploits differences in 1H spin diffusion. The characteristic diameter of a PEO domain is 4.8 +/- 1.4 nm and that of PC is 5.2 +/- 1.4 nm with a mixed phase region of 0.8 +/- 0.5 nm.

[Detection of verotoxin-producing E. coli in field isolates from domestic and agricultural animals in Sachsen-Anhalt]

A report is given on the detection of verotoxin-producing E. coli (VTEC) strains from field isolates of healthy or ill cattle (n = 141), pigs (n = 306), sheep (n = 15), cats (n = 29) and dogs (n = 25) in the region of the new federal land Sachsen-Anhalt. 5% of the strains isolated from cattle, 32% from pigs, 20% from sheep, 4% from dogs and 0% from cats have shown VTEC. The E. coli-strains were checked for the presence of other factors of virulence, too. A good correlation (82%) was found between the colonization factor F107 and SLT 2/2v-containing strains from pigs in the region of Sachsen-Anhalt, too. Enterohemolysin was not found in SLT 2/2v-positive strains. 91% of the VTEC, isolated from pigs, produced alpha-Hemolysin. The correlation of SLT-containing strains and the production of enterohemolysin was confirmed for ruminants, only. Plasmidprofilings of VTEC from pigs showed mainly a 60 MDa or a 68 MDa plasmid or both, too. The occurrence of heat labile (LT) and in some cases of heat stable (ST) toxin was also checked, to differentiate the VTEC-strains from the enterotoxigenic E. coli strains (ETEC). These investigations showed, that VTEC produce SLT almost without exception. Correlations and conclusions on the pathogenicity for humans are discussed.

Presence of anti-CSL antibodies in the cerebrospinal fluid of patients: a sensitive and specific test in the diagnosis of multiple sclerosis

The carbohydrate-binding protein (lectin) CSL is an antigen involved in the stabilization of the myelin structure by interacting with the carbohydrate moiety of myelin glycoproteins. Since anti-CSL Fab fragments were able to produce destruction of CNS myelin in vitro, CSL was considered as a potential immunological target in multiple sclerosis. The presence of anti-CSL antibodies has been examined in the cerebrospinal fluid of 1388 different patients with various neurological diseases. It is concluded that the presence of anti-CSL antibodies in the cerebrospinal fluid of patients less than 50 years old constitutes a very sensitive and specific test for multiple sclerosis.

Differential expression of an endogenous mannose-binding protein R1 during muscle development and regeneration delineating its role in myoblast fusion

The role of the endogenous brain carbohydrate-binding protein R1 in muscle cell development and regeneration was analysed both in vivo and in vitro. In vivo, R1 was developmentally regulated, with an embryonic 65,00 subunit and a neonatal 67,000 subunit, being replaced progressively by a 135,000 adult form. Lectin R1 was intracellularly localized at birth and in the prenatal period. During development and at the time of myoblast fusion, the antigen was progressively found at the surface, where it remained at low levels in the adult. In vitro, in pure myoblast cultures, only the embryonic form was present. The ultrastructural studies indicated that the lectin could participate in the membrane fusion process during myoblast fusion. The specific role in myoblast fusion, derived from the ultrastructural localization of R1, was evidenced by a strong inhibitory effect of anti-R1 Fab fragments (10-100 micrograms/ml), relative to control Fab fragments. In vivo, the embryonic subunit pattern and subcellular distribution of R1 reappeared in muscle cells after lesion of the adult muscle. This suggested that, as observed in vitro, R1 participated in vivo in the phenomenon of myoblast fusion. Similar modifications in subunit expression were observed in muscles after denervation (the embryonic form of lectin R1 reappearing after lesion), suggesting that R1 could be involved in the process of neuromuscular junction formation. Thus, it is proposed that the carbohydrate-binding protein R1 is an important recognition molecule for the formation of myotubes. Its potential involvement in a recognition process between axons and muscle cells during neuromuscular junction formation is discussed.

Neurite outgrowth of neurons of rat dorsal root ganglia induced by new neurotrophic substances with guanidine group

In order to search for compounds mimicking the neurotrophic activities, a series of substances possessing the guanidine group of isaxonine (2-isopropylamino-pyrimidine), were synthesized and tested for their ability to induce neurite outgrowth in cultures of explants of rat dorsal root ganglia. It is reported that several of these compounds, at concentrations ranging from 10(-5) to 10(-7) M, showed important effects on neurite outgrowth in vitro, similar to that obtained with the nerve growth factor NGF. These effects were found to be additive to that of NGF.

Nutritional support in the hypermetabolic patient

A patient who has experienced a major injury needs to undergo a careful assessment for hypermetabolism and malnutrition. Metabolic supportive therapy focuses on the support of the structural and functional integrity of organs and organ systems. The principles are derived from an understanding of the metabolic and physiologic responses to injury. When supportive therapy is applied in this manner, the chance of recovery can be significantly affected.

Lesion-induced re-expression of neonatal recognition molecules in adult rat cerebellum

It has been previously shown that sectioning of parallel fibers in the cerebellar molecular layer of adult rats gave rise to rapid reinnervation of the target cells, i.e., Purkinje cells. This paper reports that such a reinnervation is accompanied by reexpression (partial and total) of two developmentally regulated complementary molecules. These are an endogenous mannose-binding lectin, called R1, which reappears at the surface of the dendrites of Purkinje cells, and an endogenous glycoprotein ligand of R1, the 31 kDa glycoprotein, which seems to be neosynthetized and transported to the surface of parallel fibers. In this system, embryonic N-CAM is not reexpressed in neurons but reappears in reactive astrocytes in the vicinity of the lesion. The reexpression of recognition molecules (lectin and glycoprotein ligand) involved in normal synaptogenesis, may constitute the molecular basis for repair of nervous circuits in the adult as well.

Therapeutic listening: key intervention for several nursing diagnoses

Listening is the intervention of choice for several nursing diagnoses common to critically ill patients. Yet, because the patients often cannot talk long and nurses are busy, listening can be difficult to implement in critical care.

Glycoproteins and lectins in cell adhesion and cell recognition processes

The discovery of endogenous lectins having specific and high affinity for the carbohydrate portions of glycoproteins has opened up new directions in the field of cell adhesion and cell recognition. Two endogenous lectins, termed as CSL and R1, initially isolated from the rat cerebellum and having a wide distribution in mammalian tissues, have been shown to participate in essential mechanisms of cell adhesion. The membrane-bound lectin R1 seems to be involved in transient recognition between neuronal cells, followed by elimination of the glycoprotein ligands at the surface of the recognized cell. In contrast, CSL is a molecule involved in adhesion between various normal or transformed cells since it participates in the formation of tight junctions. The glycoprotein ligands recognized with higher affinity by these two lectins seem to possess a special structure which defines a sub-class of oncofetal HNK-1 glycans. The over-expression of the glycoprotein ligands of these lectins in most transformed cells provides new tools for understanding the underlying mechanism of malignant transformation as well as the generation of signals through cell adhesion.

Endogenous lectin cerebellar soluble lectin involved in myelination is absent from nonmyelinating Schwann cells

In the sciatic nerve, two major classes of Schwann cells are present which differ in their capability to produce myelin. Myelinating Schwann cells surround most of the axons with the formation of a typical myelin sheath. Nonmyelinating Schwann cells serve to insulate individual axons without formation of myelin. These dissimilarities between the two types of Schwann cells provided an interesting model for studying mechanisms underlying myelination and the formation of contacts between axons and myelinating cells. It is demonstrated here that the endogenous lectin cerebellar soluble lectin (CSL), implicated in myelin stabilization and in formation of contact between axon and myelinating cells in the CNS and in the sciatic nerve, is undetectable in non-myelinating Schwann cells. In contrast, most axons surrounded by these cells contained the major axonal glycoprotein ligand of CSL, a 31-kDa glycoprotein which is present in large amounts. The possible relationship between the presence of CSL in Schwann cells and their capacity to interact with axons and to produce myelin are discussed.

Cerebrospinal fluid anti-cerebellar soluble lectin antibodies in human immunodeficiency virus type 1 infection

Cerebrospinal fluid samples from 14 human immunodeficiency type 1 (HIV-1) seropositive patients in various stages of HIV infection were tested for the presence of autoantibodies to an endogenous manose-binding protein, the cerebellar soluble lectin (CSL), which has recently been found to be detected in a high proportion of patients with multiple sclerosis. An immunoblotting test was used with rat CSL as antigen. Seven patients were positive for anti-CSL and seven were negative. The seven anti-CSL-positive patients had signs of intrathecal immunoglobulin G production measured as an elevated IgG index, while the seven anti-CSL-negative patients had a normal IgG index. There was no apparent relation between infectious stage and the presence of anti-CSL. Immunological reactions such as anti-CSL autoantibodies may be a similar pathogenic mechanism in HIV and multiple sclerosis brain disease.

Growth hormone and nutritional support: adverse metabolic effects

The use of growth hormone in clinical nutritional support has received considerable attention over the past decade. The most encouraging results have been improved nitrogen retention and protein synthesis in the presence of hypocaloric nutritional support. Adverse effects, however, can limit the clinical usefulness of this technology. In the following case study, an obese 71-year-old man with a history of chronic obstructive pulmonary disease remained ventilator dependent 2 months following anterior cervical fusion and had severe depletion of visceral proteins despite nitrogen equilibrium. He was treated with 10 mg of recombinant human growth hormone (Genentech) subcutaneously every other day while also receiving nutritional support. We hypothesized that growth hormone administration could promote both protein synthesis and the development of muscle mass, particularly in the respiratory muscles, without increasing nutrient intake and, therefore, without increasing CO2 production. The patient, however, developed two potentially life-threatening adverse effects: hyperglycemia and fluid retention. The severity of these adverse effects led to discontinuation of this mode of therapy.

Involvement of the endogenous lectin CSL in adhesion of Chinese hamster ovary cells

Immunochemical localization of an endogenous mannose-binding protein, the cerebellar soluble lectin (CSL; Zanetta et al., J. Neurochem. 49, 1250-1257 (1987)), in Chinese hamster ovary cells indicated its high concentration in areas of contact between cells. This suggested its role in cell adhesion. The pattern of staining differed significantly in the cells cultured in suspension from that grown as monolayer. In cells maintained for a short time as suspension, the extracellular CSL immunoreactivity was found mainly in close apposition to the plasma membrane including contact areas. In cells cultured as monolayer, extracellularly, the lectin was found both at the cell surface and in a 75-nm thick layer between two cells, apparently adhering to the cell surface through bridges. Endogenous glycoprotein ligands of CSL were present in the cultures of CHO cells, both as membrane-bound glycoproteins and as glycoprotein ligands soluble in the presence of mannose in the absence of detergent. The lectin CSL induced adhesion between these cells as evident by low concentration of anti-CSL Fab fragments inhibiting such adhesion. These data suggested that adhesion between CHO cells occurs, in part, through a glycobiological recognition system involving CSL. This mechanism should be taken into account for the interpretation of experiments of transfection in CHO cells of the genes of glycoproteins involved in cell adhesion.

[Detection and characterization of Salmonella strains from laughing gulls (Larus ridibundus)]

25 and 17 Salmonella strains could be isolated from 429 and 423 blackheaded gulls (Larus ridibundus), respectively, during two years of examination. S. typhimurium was the most frequent serovar. All strains of S. typhimurium belonged to the biochemovar c (inosite and rhamnose negative), nearly a third of isolates caused a mannose-sensitive hemagglutination of guinea pig erythrocytes. This result is in contradiction to the literature. Furthermore the phagovars, the plasmid profiles and the resistance against chemotherapeutics were tested. The Salmonella carriage by gulls presumably reflects the contamination of the environment.

Improvement in immune function in ICU patients by enteral nutrition supplemented with arginine, RNA, and menhaden oil is independent of nitrogen balance

Hypermetabolism and multiple organ failure syndrome (MOFS) after trauma, surgery, or sepsis is associated with accelerated catabolism, the rapid onset of malnutrition, and immune system failure. Current nutritional support, enteral or parenteral, can achieve an acceptable nutritional response but appears unable to improve immune function. Nutrients such as arginine, refined menhaden oil, and RNA have been found to have immune-stimulating properties. This randomized blind prospective trial compared two nutritionally complete enteral formulas, one supplemented with arginine, menhaden oil, and RNA, on the disease-specific effects of anergy and suppression of in vitro tests of immune function in intensive-care patients and the nutritional outcome of nitrogen balance. After 7-10 days of enteral nutrition in patients with persistent sepsis syndrome, both formulas were associated with the achievement of net nitrogen retention and improved visceral protein status but with nonresolution of anergy. However, the supplemented formula was associated with marked stimulation of in vitro lymphocyte proliferative responses and a significant reduction in 3-methylhistidine excretion. Six and 12-mo follow-up data demonstrated no long-term effects. Nutrients targeted to effect the disease-induced in vitro suppression of immune function in MOFS appear to achieve that end independent of the nutritional outcome of nitrogen balance and without adverse clinical outcome.

Epidemiological and experimental studies on a new incident of transmissible mink encephalopathy

Epidemiological investigation of a new incident of transmissible mink encephalopathy (TME) in Stetsonville, Wisconsin, U.S.A. in 1985 revealed that the mink rancher had never fed sheep products to his mink but did feed them large amounts of products from fallen or sick dairy cattle. To investigate the possibility that this occurrence of TME may have resulted from exposure to infected cattle, two Holstein bull calves were injected intracerebrally with mink brain from the Stetsonville ranch. Each bull developed a fatal spongiform encephalopathy 18 and 19 months after inoculation, respectively, and both bovine brains passaged back into mink were highly pathogenic by either intracerebral or oral inoculation. These results suggest the presence of a previously unrecognized scrapie-like infection in cattle in the United States.

[Is Cerebellar Soluble Lectin a major immunological target in multiple sclerosis?]

In a recent paper: (Zanetta J.P. et al., Lancet, 1990, 335, 1482-1484) the authors showed that antibodies against the mannose-binding protein Cerebellar Soluble Lectin (CSL) are present in the cerebrospinal fluid of most multiple sclerosis patients. Herein, the properties and roles of the molecule as they are currently understood are described; hypotheses suggested by the consistent presence of anti-CSL antibodies in multiple sclerosis patients are discussed.

An endogenous lectin and one of its neuronal glycoprotein ligands are involved in contact guidance of neuron migration

In the central nervous system, postmitotic neurons migrate along astrocytic processes to reach their adult position. The molecular mechanisms of this guided migration are not clearly defined, although some steps have been shown to involve proteases and cell adhesion molecules. We report that monovalent antibodies (Fab fragments) raised against an endogenous cerebellar soluble lectin (CSL) completely inhibit neuronal migration in cultures of cerebellar explants at concentrations as low as 50 micrograms/ml. A similar inhibition pattern was obtained with Fab fragments prepared against one of the endogenous glycoprotein ligands of CSL, the 31-kDa glycoprotein (this glycoprotein is a membrane-bound glycoprotein specifically occurring, in the cerebellum, at the surface of immature neurons). We propose that this lectin-glycoprotein interaction supports the adhesion between neurons and the astrocyte guide during the migration of cerebellar immature neurons.

Antibodies to cerebellar soluble lectin CSL in multiple sclerosis

Cerebrospinal fluid samples from 239 patients with various neurological disorders were tested for the presence of autoantibodies to an endogenous mannose-binding protein, the cerebellar soluble lectin CSL, by means of an immunoblotting test with rat CSL as antigen. 47 of 51 patients with multiple sclerosis were positive for anti-CSL compared with 30 of 188 patients with other neurological disorders. 14 of the 30 false-positive patients were over 60 years old, an age group not typical of multiple sclerosis patients. The specificity of the test for multiple sclerosis was 85% and the sensitivity 93.5%. The possibility that CSL is an important immunological target in multiple sclerosis allows new insights into the possible causes and development of this disorder.