Increase in signal intensities on T1-weighted magnetic resonance images in asymptomatic manganese-exposed workers

OBJECTIVES: To clarify the clinical significance of increased signal intensities on T1 weighted magnetic resonance imaging (MRI) we performed a large-scale epidemiological study on asymptomatic manganese (Mn)-exposed workers with its focus on MRI. METHODS: We randomly selected 121 male workers out of a total of 750 workers including Mn-exposed, non-exposed manual, and non-exposed clerical workers in the factories. We studied environmental and biological monitoring, neurological examination, and MRI. RESULTS: The proportion of workers with increased signal intensities among the exposed, the non-exposed manual workers, and the non-exposed clerical workers was 46.1%, 18.8%, and 0%, respectively. Especially, 73.5% of the welders showed increased signal intensities. In no subject, were clinical signs of manganism observed. The pallidal index correlated with blood Mn concentration. CONCLUSION: Increase in signal intensities on the T1-weighted image reflect recent exposure to Mn, but not necessarily manganism. At which increase of signal intensity, the progression of manganism from Mn exposure occurs, remains to be solved.     

c-Fos basal immunoreactivity decreases in rat spinal cord during normal ageing

The pattern of distribution in rat spinal cord and changing pattern during normal ageing of c-Fos expression were investigated by immunohistochemical staining in male Sprague-Dawley rats at the age of 1 week, 5 months and 2 years. c-Fos immunoreactivity was observed diffusely in gray matters in neonatal rats, preferentially located in deep dorsal horn and around central canal. Compared with those of neonatal rats, these cells decreased prominently in adult rats. In aged rats, immunoreactive cells were not seen in any segments. c-Fos immunoreactivity in spinal cord may be related to stress response, functional differentiation, and in part, neuronal death with target dependence. In conclusion, we demonstrated for the first time that c-Fos expression patterns change during normal ageing.     

Distribution of proteoglycans in the human trabecular meshwork: histochemical electron microscopic findings with cuprolinic blue

The distribution of sulfated proteoglycans (PGs) in the normal human trabecular meshwork was studied by histochemical electron microscopy using the cationic dye, cuprolinic blue (CB).. The trabecular meshwork was obtained from human enucleated eyes and incubated for three days. After incubation, they were stained with 0.2% CB at a critical electrolyte concentration and prepared for histochemical electron microscopy. Ultrastructurally, PG-CB complexes were found as small punctate or filamentous structures, and were associated with collagen fibrils in the cores of the trabecular beams and the basal laminae of trabecular endothelial cells. In addition, large filamentous PG-CB complexes were mainly associated with areas of amorphous extracellular matrix between the collagen fiber bundles and in the fine fibrillar material near the basal laminae of endothelial cells of Schlemm's canal. This investigation resulted in an illustration of the ultrastructural distribution of PGs in the human trabecular meshwork. Further studies will be needed to specify the nature of PGs and their role in the aqueous outflow system.     

Cytotoxic constituents from the roots ofAnthriscus sylvestris

Activity-guided fractionation of the roots of Anthriscus sylvestris resulted in the isolation and characterization of five cytotoxic compounds, deoxypodophyllotoxin (1), falcarindiol (2), and angeloyl podophyllotoxin (5) from the hexane soluble fraction and morelensin (3), bursehernin (4) from the chloroform soluble fraction. It is the first report of the occurrence of compound 5 in nature.     

Biomarkers in airway tumors

Despite advances and improvements in diagnosis and treatment of upper aerodigestive tumors including head and neck and lung cancers, the overall survival rate of these patients remains poor. Prevention, early diagnosis, and novel therapy are under active investigation to improve the outcome of the diseases. In particular, chemopreventive strategy is a novel approach to reduce the invasive tumors by reversing the premalignant lesions with certain differentiating agents (i.e., retinoids). To conduct effective chemopreventive trials, there has been a great surge of interest in defining the biomarkers associated with the specific stages of the carcinogenesis and with intermediate end points during the therapy. Carcinogenesis in the upper aerodigestive tract has been explained by two theories, field cancerization and multistep process. The driving forces behind these processes are noted by accumulated genetic abnormalities in the entire epithelium of the airway. These genetic abnormalities include chromosome abnormalities, specific gene alterations (i.e., ras gene family, tumor suppressor genes, growth factors and their receptors), and proliferation and differentiation markers. These biomarkers are herein described in this review article.     

Evaluation of a new solution containg trehalose for twenty-hour canine lung preservation

We examined the efficacy of two new preservation solutions containing trehalose-an extracellular type (ET-K) of solution and an intracellular type (IT-K) of solution — in relation to that of Euro-Collins (EC) solution in 20-h canine lung preservation. Canine lungs were flushed with one of the three solutions (n=5 for each solution) after pretreatment with PGE₁ (20 g/kg) and were stored for 20 h at 4°C. The left lungs were transplanted and evaluated to 6 h post transplant. In the ET-K group, the arterial oxygen tension after reperfusion was significantly higher than in the IT-K and EC groups. The pulmonary vascular resistance, wet/dry weight ratio, and histological evaluation of each transplanted lung in the ET-K group were also better than in the IT-K and EC groups. This indicates that ET-K solution is useful for 20-h preservation of canine lung grafts.     

Long-term outcome in 134 patients with galactosaemia

In a retrospective study 134 galactosaemic patients, born between 1955 and 1989 in the Federal Republic of Germany were traced and their long-term outcome evaluated. We investigated 83 galactosaemic patients (78 homozygotes, 5 compound heterozygotes) by clinical, psychometric and laboratory testing; 31 patients were evaluated by medical history, the remaining 20 patients had died due to sequelae of the underlying disease. In 48 out of 78 classical galactosaemia patients galactose-free therapy had been started before the 15th day, in 19 between days 15 and 56 and in 11 patients after the 56th day. Physical findings revealed that puberty was delayed in 1 out of 18 males and 6 out of 11 females. Neurological abnormalities included ataxia (n=6), intention tremor (n=11) and microcephaly (n=10). Speech abnormalities were found in 43 out of 66 patients over 3 years of age and disturbance of visual perception and/or arithmetic deficits in 29. Intelligence declined with age, i.e., a DQ or IQ less than 85 was found in 4 out of 34 patients less than 6 years of age (12%), in 10 out of 18 between 7 and 12 years (56%) and in 20 out of 24 older than 12 years (83%). Metabolite patterns (RBC galactose-1-phosphate and UDP-galactose, plasma and urinary galactitol) did not correlate with DQ or IQ. Dietary compliance was good in almost all patients. Compound heterozygotes (n=5) had normal mental and growth development and all laboratory parameters were in the normal range. The cause of the unsatisfactory outcome of well-treated galactosaemic patients with disturbances in long-term development remains unclear. This could be due to a chronic intoxication of galactose metabolites or a deficiency of UDP-galactose or galactose-containing glycoproteins or glycolipids.This study was supported by a grant from the Stifterverband für die Deutsche Wissenschaft (Huebner-stiftung), grant TS 114/18/89 and by the Arbeitsgemeinschaft für Pädiatrische Stoffwechselstörungen     

A study on analysis of particle size distribution

Analysis of particle size distribution of a sample of fine aluminum hydroxide powder was carried out by four different methods,i. e., conductivity, air permeability, gas-adsorption and sedimentation. Each method was reproducible. The results obtained by Coulter counter and sedimentation balance were similar, and the data obtained by Lea and Nurse permeameter and Stroehlein areameter were also similar. But the results differ considerably between the former and the latter. The advantages and disavantages of each method were discussed briefly and a means of comparing the results with those obtained by surface area measurements was shown.     

Studies on corneal penetration ofp-hydroxybenzoic acid esters

Corneal permeability of variousn-alkylp-hydroxybenzoates (parabens) was studiedin vitro using excised rabbit corneas, and the effect of lipophilicity of parabens on the corneal permeability was also investigated. Permeability coefficients were obtained from the least-square linear regression after the steady state had been reached. Lipophilicity of parabens was calculated by distribution coefficients determined in octanol-S \(12_\phi [\kern-0.15em[ \) rensen’s buffer solution (pH 5.0). The relationship between lipophilicity and corneal permeability of parabens was not linear, but the optimum lipophilicity for the maximum permeation was found. The influence of tween 80 on corneal permeability of methyl and butylparaben was not significant.