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Methodological aspects of quantitative X-ray microanalysis of semi-thick cryosections (2--6 micrometers) of biological soft tissue were investigated. The preparation of a low background specimen holder is described. Scanning and scanning transmission images of the sections could be obtained, allowing identification and separate analysis of nuclei and cytoplasm. Parallel observations of histochemically stained adjacent sections in the light microscope allowed correlation of the microanalytical data with tissue morphology and histochemistry. Quantitative analysis could be carried out with the help of a standard: a gelatin/glycerol matrix containing mineral salts in known quantities, frozen and sectioned in the same way as the specimen. Mass loss under the electron beam was found to be comparable in specimen and standard. Comparison of various theoretical models for quantitative analysis showed that the 'P/B-method' (determination of the background intensity under the characteristic peak) is the most suitable for semi-thick sections. Factor determining the choice of accelerating voltage were analyzed. The usefulness of this specimen type is illustrated in some biological applications (human oral mucosa, rat salivary gland).

One hundred seventy-eight patients with transient ischemic attacks (TIAs) or small strokes with slight symptoms persisting for more than 24 hours (incomplete recovery = IR) (TIA-IR) from both the carotid and the vertebrobasilar systems were treated with anticoagulants. Ten patients stopped the treatment because of severe side effects. Only one patient had a lethal cerebral infarction when the thrombotest values were above the therapeutic level; no other infarction happened during the treatment period. Moreover, the frequency of TIA decreased during the treatment, compared with descriptions of the natural course of TIA. One hundred four patients were observed for a mean of 21 months after the anticoagulant treatment ended. During the observation period, six patients had cerebral infarctions. This was a sixfold increase compared with the stroke incidence during treatment, and was almost identical with the incidence of strokes seen during the natural course of TIA. All the cerebral infarctions were in patients who had their initial TIA/TIA-IR from the carotid territory (within the same carotid artery which earlier had given symptoms). The investigation shows that long-term anticoagulant treatment is useful, especially in patients with carotid TIA/TIA-IR, and that this treatment should continue as long as the patients can manage it. In patients with vertebrobasilar symptoms of malignant character, it seems feasible to terminate the treatment after about one year. The mechanism of the anticoagulant treatment is obscure, but it does not appear to influence the progress of the atherosclerotic process.

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Cerebrospinal fluid (CSF) samples obtained by consecutive lumbar puncture of 26 patients with presumed pale cerebral infarction, 66 with presumed hemorrhagic infarction, 16 with lobar hematoma, and 18 with cerebral infarction verified at autopsy, were examined with a cytological method permitting a total and differential cell count. A transitory outflow of polymorphonuclear neutrophilic leukocytes (PNL) was found in 70% of the patients with hemorrhagic infarction and lobar hematoma, with a peak three to four days after onset. The strongest PNL reaction was recorded in CSF from patients with lobar hematoma. In 75% of patients with pale infarction, no PNL or only a few PNL were found. In the autopsy group the PNL reaction in the brain as well as in the CSF was stronger in patients with hemorrhagic infarcts than in those with pale infarcts. (26:489-501, 1972) Key Words.\p=m-\Cerebrospinalfluid cytology; differential diagnosis of stroke; brain infarction; lobar hematoma; cerebrospinal fluid in cerebro-$ vascular disease.

In order to determine whether or not atropine, procaine, and tetrodotoxin (TTX) can stimulate intestinal smooth muscle directly, we examined the effects of these drugs on the mechanical and electrical activities of several types of cat intestinal smooth muscle preparations. The preparations consisted of isolated rings of 1) intact intestinal wall, 2) intact longitudinal and circular muscle, 3) ganglion-free circular muscle, and 4) ganglion-free circular muscle devoid of its dense layer and plexus muscularis profundus. Atropine and procaine (greater than 10(-4) M) stimulated all four types of preparation. On the other hand, TTX (up to 5 X 10(-6) M) stimulated only preparations 1 and 2. It is concluded that whereas atropine and procaine can directly stimulate intestinal smooth muscle, the excitatory effect of TTX is neurally mediated.

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