Fulminant Guillain-Barré syndrome with universal inexcitability of peripheral nerves: a clinicopathological study

The pathological basis of nerve inexcitability in Guillain-Barré syndrome has not been established with certainty. We report the clinicopathological findings in a 67-year-old patient with fulminant Guillain-Barré syndrome who died 18 days after onset. Three serial electrophysiological studies revealed nerve inexcitability. Antibodies to Campylobacter jejuni were present but there was no antiganglioside reactivity. Spinal root sections revealed extensive and almost pure macrophage-associated demyelination with occasional presence of T lymphocytes and neutrophil leukocytes. Conversely, in femoral, median, and sural nerves the outstanding lesion was axonal degeneration, with some denuded axons remaining. Unmyelinated fibers, posterior root ganglia, and dorsal columns were preserved. Endoneurial postcapillary venules showed plump endothelial cells with loss of their tight junctions. We conclude that both primary demyelination and axonal degeneration secondary to inflammation account for nerve inexcitability. Our findings lend support to the hypothesis of increased endoneurial pressure as the cause of wallerian degeneration in nerve trunks.     

Role of nitric oxide in the regulation of the hepatic microcirculation in vivo

BACKGROUND/AIMS: Nitric oxide (NO) is an important mediator in the regulation of vascular tone. However, no data exist on the physiological role of NO in the regulation of the hepatic microcirculation. This study was designed to evaluate the role of NO in the hepatic microcirculation in vivo under physiological conditions. METHODS: The hepatic microcirculation was investigated in anesthetized rats by intravital fluorescence microscopy after injection of fluorescein-isothiocyanate-labeled erythrocytes. Following assessment of baseline sinusoidal perfusion, animals were randomly treated with L-NMMA (n=6), L-arginine (n=6), nitroprusside sodium (NPS, n=5) or a comparable volume of NaCl (n=4). Drugs were given through a portal vein catheter at three doses (Dx), each followed by intravital microscopy. L-NMMA was given: 5 mg/kg (D1), 25 mg/kg (D2), 50 mg/kg (D3); L-arginine 30 mg/kg (D1), 150 mg/kg (D2), 300 mg/kg (D3); and NPS continuously 80 microg x kg(-1) x h(-1). RESULTS: L-NMMA induced a significant increase of mean arterial blood pressure (MAP) (114 vs. 129 mm Hg; p<0.05). In contrast, MAP of NPS-treated animals decreased (107 vs. 91 mm Hg; p<0.01) whereas MAP of animals receiving L-arginine did not significantly differ. Sinusoidal blood flow revealed dose-dependent changes: L-NMMA significantly decreased perfusion of sinusoids (D1: 65%, D2: 57%, D3: 50% of baseline, p<0.05). Injection of L-arginine increased the sinusoidal flow even with the lowest dose (D1: 137%, D2: 133%, D3: 123%, p<0.05). Continuous infusion of NPS had little effect on sinusoidal blood flow at the first and second times of microscopy but sinusoidal blood flow was significantly increased at the third time (D1: 103%, D2: 106%, D3: 122%). CONCLUSIONS: Inhibition of NOS results in a dose-dependent disturbance of the hepatic microcirculation despite significantly increased MAP, whereas L-arginine increases the sinusoidal blood flow. The results indicate an important role for NO in the regulatory mechanisms of hepatic sinusoidal perfusion under physiological conditions.     

On singular topologies in exact layout optimization

The causes of singular structural topologies, which prevent most iterative computational algorithms from reaching the global optimal solution, are explained in the light of the theory of exact optimal layouts. This theory is also used for deriving eight fundamental characteristics of singular topologies. The above findings are illustrated with case studies of exact optimal layouts for a single load and for two load conditions with stress constraints.     

Strengthening of soils during construction under chalk karst conditions

The experience of the State Joint-Stock Company for Stabilization of Bases and Structures (Gidrospetsstroi) in eliminating a technogenic chalk karst under complex hydrogeological conditions is reported. The causes of formation of the karst at a depth of 30–40 m and methods of eliminating piping and karstification by injecting cement grouts into the chalk by a special technology are examined. Translated from Osnovaniya, Fundamenty i, Mekhanika Gruntov, No. 3, pp. 21–23, May–June, 1994.     

A method of calculating the compression deformation modulus of sandy and gravelly soils

A method based on use of Hardin's homogeneous model is proposed for calculation of the deformation modulus of noncohesive soils. Completely satisfactory correspondence between computed and experimental values of the deformation modulus of sands is demonstrated. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 4, pp. 2–5, July–August, 1994.     

Cardiac risk in surgery. A review and guidelines for risk evaluation and reduction of cardiac risk in general surgery

We report herein the phenotypic and functional analysis of human bone marrow and thymus derived early T cells. Commitment to T cell lineage is acquired during CD7 antigen expression by CD34+ precursors in human bone marrow and before thymus colonization. Early thymocytes show similar phenotypic characteristics as bone marrow T cells. They rapidly acquire CD4 before the dual expression of CD4 and CD8. Their expansion and differentiation is regulated by two major factors: thymic stroma and cytokines produced by these stroma cells or by thymocytes themselves. Among cytokines, IL1 and sCD23 produced by thymic epithelial cells support in vitro early T cell development.     

The anti-tumor arotinoid Ro 40-8757 protects bone marrow from the toxic effects of 5-fluorouracil

We have previously shown that strychnine mimics the cytoprotective properties of glycine in renal proximal tubule (RPT) suspensions exposed to antimycin A (AA). The aims of this study were to determine whether the cytoprotective properties of strychnine applied to various types of nephrotoxicants and to examine the temporal aspects of the cytoprotection of glycine and strychnine. Tubular release of LDH activity was used as a marker of cell death. Glycine (2 mM) or strychnine (1 mM) added 5 min prior to the toxicant decreased LDH release in rabbit RPT suspensions exposed to 25 microM tetrafluoroethyl-L-cysteine (TFEC), 10 microM HgCl2, 0.5 mM t-butyl hydroperoxide (TBHP), or 0.2 mM bromohydroquinone (BHQ) for 4 hr, or 2 mM sodium cyanide (NaCN) for 2 hr. The relative rank order of effectiveness of glycine and strychnine was NaCN = TFEC > BHQ > DCVC > TBHP > HgCl2. The temporal aspects of strychnine and glycine protection were examined by exposing RPT to either AA or TFEC for 1 or 3 hr, respectively, and then adding either 1 mM glycine or 1 mM strychnine. Glycine and strychnine decreased LDH release in AA-treated RPT at 1.25 and 2 hr and TFEC-treated RPT at 4 hr. In addition, when RPT exposed to AA or TFEC and treated with strychnine or glycine were washed at either 1 or 4 hr, protection was eliminated at later time points. When glycine was added to RPT treated with either PCBC, TFEC, or DCVC 5 min prior to or 30, 60, 120, and 180 min following toxicant addition, LDH release was reduced at all time points. These results demonstrate that strychnine and glycine protect RPT from a variety of diverse nephrotoxicants, strychnine and glycine do not need to be present at the time of toxic insult, strychnine and glycine cytoprotection is reversible, and strychnine and glycine act in the late phase of necrotic cell injury.     

A study of urinary dolichols as a biological marker for alcohol abuse. Report 2: Comparison of urinary dolichols/creatinine concentrations among non-drinkers, moderate-drinkers and heavy-drinkers

We report here the comparison of urinary dolichols/creatine (D/Cr) concentration ratios in male non-drinkers, moderate-drinkers and heavy drinkers at admission and during hospitalization, and also discuss its usefulness as a biological marker for alcohol abuse. Urine samples were collected from the following four experimental groups: non-(male and female) and moderate-drinker (male) volunteers, and alcoholic heavy-drinking patients (male) at admission for psychiatric treatment and after 9-15 days hospitalization (informed consent was obtained). Urinary dolichols were determined by high performance liquid chromatography after BondElutC18 (500 mg) extraction. Due to significant differences in urinary D/Cr concentrations between male and female groups in non-drinkers and because the heavy-drinkers available for this study were exclusively male, comparison of the value of urinary D/Cr concentration ratios was subsequently limited to male only. There were no statistical differences in urinary D/Cr concentrations in the male among non-drinkers, moderate-drinkers and heavy-drinkers at admission. The accuracy of urinary D/Cr as a biological marker for alcohol abuse, calculated using the mean +/- 2 s.d. in non- and moderate-drinkers as the normal range, is only 33.3% in heavy-drinkers at admission, while their value of gamma-GTP in serum was 88.3%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Metabolism of tetramethrin isomers in rat: II. Identification and quantitation of metabolites

1. To examine the metabolic fate of (1RS, trans)- or (1RS, cis)-tetramethrin [3, 4, 5, 6-tetrahydrophthalimidomethyl (1RS, trans)- or (1RS, cis)-chrysanthemate], rat was administered a single oral dose of trans- or cis-[alcohol-14C]tetramethrin at dose levels of 2 or 250 mg/kg. 2. The radiocarbon was almost completely eliminated from rat within 7 days after administration in all groups. 14C-recoveries (expressed as percentages relative to the dosed 14C) in faeces and urine were 38-58 and 42-58% respectively in rat administrated trans-[alcohol-14C]tetramethrin, and in faeces and urine were 66-91 and 9-31% respectively in rat administered cis-[alcohol-14C]tetramethrin. 3. Fourteen metabolites found in excreta were purified by using several chromatographic techniques and identified by spectroanalyses (nmr and MS). Five sulphonate derivatives and three dicarboxylic acid derivatives were found. 4. The main metabolites were sulphonate derivatives in the faeces, and in the urine, alcohols, dicarboxylic acid and reduced metabolites derived from the 3,4,5,6-tetrahydrophthalimide moiety.