Neurotoxic effects of organic solvents in exposed workers: an occupational, neuropsychological, and neurological investigation

Ninety-eight workers, 65 exposed to organic solvents and 33 unexposed, were examined in order to assess possible neurotoxic signs and symptoms related to solvent exposure. The study group, who were selected according to the type of exposure in a given work process, had been exposed to various types of solvents. The groups were comparable in regard to age, the history of brain traumas and other neurological diseases, and alcohol consumption. The exposed workers had more symptoms of intellectual impairment, poorer performances in psychological tests, and more often signs of cerebral asthenopia. Symptoms and signs of peripheral neuropathy were not significantly increased. Solvent exposure and neurotoxic signs and symptoms were mildly correlated in the study group. Such dose-effect correlations have previously been proved only in a few epidemiological studies. This warrants reevaluation of the risk of developing toxic encephalopathy during prolonged occupational exposure to solvents.     

Kindling Induces Transient Changes in Neuronal Expression of Somatostatin, Neuropeptide Y, and Calbindin in Adult Rat Hippocampus and Fascia Dentata

Summary: Fully hippocampus-kindled rats were examined 1 day and 1 month after the last stimulation for changes in somatostatin (SS)-, neuropeptide Y (NPY)-, and calbindin (CaBP)-immunoreactivity (ir) and SS- and NPY-mRNA in situ hybridization (ISH). One day after the last stimulation, there was marked, bilateral increase in SS- and NPY-ir in the outer part of the dentate molecular layer. The cell bodies of dentate hilar SS- and NPY-containing neurons, known to project to this area, also appeared to display increased immunoreactivity as well as an increased ISH signal for SS and NPY mRNA. Bilateral de novo expression of NPY-ir in dentate mossy fiber projection to dentate hilus and CA3 was also evident, but we noted no corresponding NPY-mRNA signal in the parent cell bodies, the dentate granule cells. After 1 month, the levels of NPY-ir and ISH signal appeared essentially normal. In contrast, the levels of SS apparently were decreased, although not yet normal. CaBP-ir was markedly and selectively reduced in dentate granule cell bodies, dendrites, and mossy fibers 1 day after the last stimulation, but after I month CaBP-ir appeared essentially normal. Because kindling, once established, is a permanent phenomenon, the observed transient changes in SS, NPY, and CaBP in specific hippocampal terminal fields and neuronal populations cannot be associated specifically with kindling. Rather, they relate to the repeated high-frequency stimulations and may serve as protective measures against deleterious effects of such stimulations.     

Feasibility study using a Ni-Ti stent and electronic portal imaging to localize the prostate during radiotherapy.

BACKGROUND AND PURPOSE: A new method for localization of the prostate during external beam radiotherapy is presented. The method is based on insertion of a thermo-expandable Ni-Ti stent. The stent is originally developed for treatment of bladder outlet obstruction caused by benign hyperplasia. The radiological properties of the stent are used for precise prostate localization during treatment using electronic portal images. PATIENTS AND METHODS: Patients referred for intended curative radiotherapy and having a length of their prostatic urethra in the range from 25 to 65 mm were included. Pairs of isocentric orthogonal portal images were used to determine the 3D position at eight different treatment sessions for each patient. RESULTS: Fourteen patients were enrolled in the study. The data obtained demonstrated that the stent position was representative of the prostate location. The stent may also improve delineation of the prostate GTV, and prevent obstruction of bladder outlet during treatment. Precision in localization of the stent was less than 1 mm. Random errors in stent position were left-right 1.6 mm, cranial-caudal 2.2 mm and anterior-posterior 3.2 mm. In four of 14 patients a dislocation of the stent to the bladder occurred. Dislocation only occurred in patients with length of prostatic urethra less than 40 mm. CONCLUSIONS: A new method for radiological high precision localization of the prostate during radiotherapy is presented. The method is based on insertion of a standard Ni-Ti thermo-expandable stent, designed for treatment of benign prostate hyperplasia.     

Nasal salmon calcitonin in osteoporosis

Conclusion Nasal sCT is a safe drug with few and mild side effects and compared with HRT is often more attractive to elderly, osteoporotic women. Under controlled conditions, nasal sCT reduces the rate of new fractures by two-thirds compared with calcium treatment alone [10] and increases spinal bone mass dose dependently.Conclusively, nasal sCT is indicated for treating women who have passed the menopause some years ago. The treatment should be administered discontinuously. The nasal formulation has been approved for treatment of osteoporosis in a variety of European and South American countries, and has also been filed with appropriate governmental authorities for consideration of approval in many countries throughout the world, including the US. Should calcitonin treatment be generalized in women who are 10–15 years postmenopausal, the costs will undoubtedly be reduced. Compared with the effect of HRT on early postmenopausal bone loss, the effect of nasal sCT is only marginal. Thus, HRT prevents both the cortical and trabecular bone loss throughout the entire treatment period [38]. Furthermore, HRT is inexpensive and its adverse event profile has been fully clarified except in respect to the possible change in the risk of breast cancer [39]. Nasal sCT can be effective in women soon after the menopause—by decreasing the rate of vertebral bone loss and lowering the bone turnover—as an alternative to hormone replacement therapy either when estrogens are contraindicated or for women who are not candidates for estrogen therapy.     

Stereological quantitation of human brains from normal and schizophrenic individuals

The complex organization and high density of nerve cells in the human brain presents a challenge to the estimation of total cell numbers. The first unbiased counting method, the disector, was described in 1984 and has since made it possible to accurately count total neuron numbers in any region that can be defined, while excluding artifacts of earlier counting methods. The disector method has been applied to normal neocortex and to four subcortical brain regions from schizophrenics and controls. The total neuron number in neocortex in 26 normal individuals was estimated to be 25·10⁹. A 40 and 50% reduction of total nerve cell number was found in the mediodorsal thalamic nucleus and nucleus accumbens in schizophrenics, respectively. Furthermore, the Cavalieri principle has been used to estimate the volume of human cortex, white matter, central grey regions and the volume of the ventricular system in both controls and schizophrenics. As shown by these studies, the introduction of unbiased stereological methods and subsequent modifications in recent years have made it possible to estimate a number of parameters in the human brain without the biases included in most classical works. By comparison, earlier conventional counting methods have been relatively time consuming, mostly biased to a smaller or larger degree, and generally less precise. The application of these new neurostereological methods will undoubtedly provide greater confidence for future brain studies.     

Studies on urinary bladder carcinoma by morphometry,flow cytometry,and light microscopic malignancy grading with special reference to grade II tumours

Summary Biopsies from 28 patients with urinary bladder carcinoma were investigated by flow cytometry and morphometry. Histopathological grading on 1.5 µm thick glycol methacrylate sections was also performed.Nuclear profile areas, nuclear volume densities and mitotic indices were usually larger in the higher grades of malignancy. All grade I tumours were diploid and all grade III tumours were aneuploid. Out of 13 grade II tumours 8 were diploid and 5 aneuploid. In these latter five cases nuclear profile areas were at the high end of the spectrum.The data show that flow cytometry and morphometry could be a valuable tool in the diagnosis of urinary bladder carcinoma. Our data also suggest that a subdivision of the grade II tumours might be possible and meaningful in the assessment of prognosis.