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Notes: Abstract Objectives: Even low concentrations of organic solvents may cause acute effects on the human central nervous system. The German MAK (threshold limit value) of methanol is 200 ppm. The aim of this study was to investigate whether acute exposure to 200 ppm methanol causes adverse effects, measured by EEG, and moreover, whether it is possible to differentiate between sedative and excitatory effects with this method. Methods: Twelve healthy subjects were exposed for 4 h to 200 ppm and to 20 ppm (control) in an exposure chamber in a cross-over design. The EEG was recorded before (reference) and at the end of each exposure with, the subject's eyes closed and opened and during a choice reaction test (color word stress test). Spectral power was calculated by fast Fourier transformation. Subjective symptoms and effects of blinding with 20 ppm methanol were assessed by questionnaires. Results: The study was a single-blind one. During subjects' exposure to 200 ppm, their scores for prenarcotic and irritating symptoms were not different from controls. In the closed-eye condition of subjects, the spectral power of the θ-band and of some electrodes of the δ-band was significantly less at the end of exposure to 200 ppm, than that of controls. In the open-eye condition and during the color word stress test no significant changes were found. Conclusion: The changes in the θ-band suggest a slight excitatory effect of 200 ppm methanol. The effect was weak, as scores of acute symptoms did not change. With respect to our results, it is not necessary for the MAK value to be decreased.

Notes: Summary During pregnancy the rat liver shows alterations in metabolism which apparently do not to occur in the non-pregnant animal. In our study, the following metabolite concentrations and enzyme activities in the liver of pregnant and non-pregnant rats were measured after fasting periods of 6 and 12 h: malate, fumarate, isocitrate, α-keto-glutarate, glutamate, malate-de-hydrogenase, fumarate-hydratase, glutamate-dehydrogenase, isocitrate-de-hydrogenase, aspartate-aminotransferase and after 12 h fast, the concentrations of acetyl coenzyme A and citrate. These results are discussed with regard to their possible importance for the maternal and fetal energy supply.

Notes: Summary For the interpretation of curative measures in patients with cerebral tumors CT is of increasing importance. The therapeutic effects can be demonstrated by close follow-up studies without any of the disadvantage of invasive neuroradiological methods. Our investigations of 125 patients with cerebral tumors are based on volume and density determinations. The CT studies of removed or inoperable tumors followed by radiation and/or cytostatic therapy prove that the best results follow a combination of both. In the present cases however, if CT proves postoperatively, at the end of radiation or at the beginning of the application of cytostatics that there is a residual mass, a complete remission cannot be obtained.

Notes: Summary In order to determine, by CT density and volume measurements, the influence of steroid therapy on cerebral tumors, on their perifocal edema and on the uninvolved cerebral tissue, CT follow-up studies of 37 patients were analysed. In general a decrease of tumor density is to be seen within the first 10 days of therapy. Under continuous steroid application absorption coefficients then increase again, so that no cortisone effect on the tumor remains. The tumor size does not alter: in particular at no time is growth retardation detectable under cortisone therapy. Intensity and extension of the perifocal edema decrease in two stages. From this delayed course we conclude the cytotoxic component of the tumor edema to be more extensive than supposed. Deviations appear dependent on tumor histology, which should lead to individualied steroid application.

Notes: Abstract A modified cryopreservation technique for parathyroid tissue was investigated in an animal model. The modified technique was compared with a previously described method [10, 11] using a programmed freezer and also with other simplified cryopreservation techniques [1, 8]. Total parathyroidectomy was performed in 90 Sprague-Dawley rats, which were allocated to 7 groups. Group I had no autotransplantation (n=10) and group II underwent immediate autotransplantation of one parathyroid gland (n=17). In the other five groups of rats the parathyroids were cryopreserved and one gland was reimplanted after 10 days' storage in liquid nitrogen (LN) at −196°C. The following techniques for cryopreservation of the parathyroid glands were used. Group III: immediate placement in LN, n=7; group IV: immediate placement in a freezer at −20 °C, transfer to LN after 2 h, n=12; group V: immediate placement in a freezer at −80 °C, transfer to LN after 2 h, n=13, group VI: manually controlled freezing initially at a rate of 1 °C/min to −25 °C, and subsequently at 10 °C/min to −70°C before transfer to LN [8], n=19, group VII: programmed freezing at a controlled rate of 1 °C/min to −80 °C prior to transfer to LN [10, 11], n=12. Serum calcium concentrations were determined over a period of 60 days. Furthermore, the individual difference in the calcium concentration was assessed for each rat ou the basis of the calcium levels recorded preoperatively and at day 60. By 60 days after immediate autotransplantation (group II), in 15 out of 17 rats (88%) serum calcium concentrations had returned to normal values. Serum calcium had normalized by day 60 in 1 out of 7 rats (14%) in group III, 6 out of 12 rats (50%) in group IV, 7 out of 13 rats (54%) in group V, 4 out of 19 rats (21%) in group VI, 7 out of 12 rats (58%) in group VII, and in none of the 10 rats without autotransplantation (group I). In group II median calcium concentrations of 2.35 mmol/l and 2.32 mmol/l were determined preoperatively and ou day 60, respectively. The median value of 0.02 mmol/l estimated for the individual calcium differences was not statistically significant. After cryopreservation the median individual calcium concentration difference was smallest in group IV at 0.14 mmol/l (median calcium level: 2.35 mmol/l preoperatively, 2.23 mmol/l day 60). After programmed freezing the median difference was 0.28 mmol/l (median calcium level: 2.48 mmol/l preoperatively, 2.25 mmol/l day 60), 0.92 mmol/l in group I, 0.72 mmol/l in group III, 0.23 mmol/l in group V and 0.39 mmol/l in group VI. In the present experimental study, rat parathyroid glands were successfully autografted after cryopreservation using the described modified technique of freezing the glands by immediate placement in a freezer at -20 °C and transfer to LN after 2 h. The results were comparable to those obtained after controlled freezing in a programmed freezer and superior to results reported for simplified cryopreservation techniques. The suitability of this technique for human parathyroid tissue will be evaluated in a further study.

Notes: Abstract Introduction: A modified cryopreservation technique for human parathyroid tissue was compared with the standard method using a programmed freezer. Methods: Total parathyroidectomy was performed in three groups of 6-week-old Rowett nude rats. Group I (control) underwent no transplantation of parathyroid tissue (n=9). After 10 days, the rats of groups II (n=15) and III (n=15) underwent xenotransplantation of 20 mg cryopreserved human parathyroid tissue, which had been stored in liquid nitrogen at –196°C for 1–22 months prior to xenotransplantation. The parathyroid tissue was derived from 15 parathyroidectomized patients with renal hyperparathyroidism. Two tissue samples were obtained from every patient. One sample from every patient was cryopreserved by means of the technique of programmed cryopreservation: programmed freezing of human parathyroid tissue at a controlled rate of –1°C/min to –80°C prior to transfer to liquid nitrogen (group II). The second sample from every patient was cryopreserved by means of a modified cryopreservation technique: immediate placement of human parathyroid tissue in a freezer at –20°C and transfer to liquid nitrogen after 2 h (group III). Calcium and intact parathyroid hormone concentrations in serum were determined over a period of 60 days. Furthermore, individual differences in the calcium concentrations were assessed for each rat on the basis of the calcium levels recorded preoperatively and at day 60. Results: All animals in the control group developed hypocalcemia. Serum calcium concentrations returned to normal levels 60 days after xenotransplantation of parathyroid tissue, which had been cryopreserved using the modified technique (group III) in 12 of 15 rats (80%). At day 60, serum calcium had normalized in 10 of 15 rats (67%) after xenotransplantation of parathyroid tissue cryopreserved using programmed freezing (group II). After modified cryopreservation (group III), the median individual difference in the calcium concentrations was –0.16 mmol/l after programmed freezing (group II). At the end of the study, a median level of human intact parathyroid hormone of 3.5 pg/ml and 2.4 pg/ml was estimated for groups II and III, respectively. There was no statistical significant difference of the individual differences in the calcium concentrations or of the levels of human intact parathyroid hormone between groups II and III. Conclusion: Human parathyroid tissue was successfully xenografted in the present experimental study. The results obtained after cryopreservation using the described modified technique were equivalent to those recorded after controlled freezing in a programmed freezer. The simplified cryopreservation technique therefore appears to be suitable for human parathyroid tissue.

Notes: Summary On domestic pigs 2/3 gastrectomies with retention and elimination of the duodenal passage were carried out. Postprandial gastric emptying was measured scintigraphically for 4 h and compared with a control group (laparotomy only). For the semi-solid, 99mTc-labeled test meal delayed gastric emptying after elimination of the duodenal passage by Roux reconstruction could not be shown. There was no difference in gastric emptying between B-I and Roux-en-Y partial gastrectomy. Also alteration of the length of the jejunum loop from 40 to 20 cm after Roux-en-Y reconstruction had no influence on gastric emptying. Roux reconstruction (40 cm loop) in combination with truncal vagotomy led to a non-uniform gastric emptying, but there was a statistically proven acceleration compared with B-I resection. After 240 min the mean residual intragastric activity of the control group (n=5) was 47.8%, 78.9% after B–I resection (n=5), 59% after Roux reconstruction with 40 cm jejunal loop (n=5), 38.1% after Roux reconstruction with 20 cm jejunal loop (n=5) and 20.9% after Roux-en-Y (40 cm loop) with truncal vagotomy (n = 4).