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Consumers of combustible cigarettes are exposed to many different toxicologically relevant substances associated with negative health effects. Newly developed “heat not burn” (HNB) devices are able to contain lower levels of Harmful and Potentially Harmful Constituents (HPHCs) in their emissions compared to tobacco cigarettes. However, to develop toxicological risk assessment strategies, further independent and standardized investigations addressing HPHC reduction need to be done. Therefore, we generated emissions of a commercially available HNB product following the Health Canada Intense smoking regimen and analyzed total particulate matter (TPM), nicotine, water, aldehydes, and other volatile organic compounds (VOCs) that are major contributors to health risk. We show that nicotine yield is comparable to typical combustible cigarettes, and observe substantially reduced levels of aldehydes (approximately 80–95%) and VOCs (approximately 97–99%). Emissions of TPM and nicotine were found to be inconsistent during the smoking procedure. Our study confirms that levels of major carcinogens are markedly reduced in the emissions of the analyzed HNB product in relation to the conventional tobacco cigarettes and that monitoring these emissions using standardized machine smoking procedures generates reliable and reproducible data which provide a useful basis to assess exposure and human health risks. Electronic supplementary material The online version of this article (10.1007/s00204-018-2215-y) contains supplementary material, which is available to authorized users.

The popularity and the high nicotine content of the American pod e-cigarette JUUL have raised many concerns. To comply with European law, the nicotine concentration in the liquids of the European version, which has been recently released on the market, is limited to below 20 mg/mL. This limit can possibly be circumvented by technological adjustments that increase vaporization and consequently, elevate nicotine delivery. In this study, we compare vapor generation and nicotine delivery of the initial European version, a modified European version, and the original American high-nicotine variant using a machine vaping set-up. Additionally, benzoic acid and carbonyl compounds are quantified in the aerosol. Further, concentrations of nicotine, benzoic acid, propylene glycol, and glycerol, along with the density and pH value of JUUL e-liquids have been assessed. Whereas the initial European version did not compensate for the low nicotine content in the liquid, we provide evidence for an increased vaporization by the modified European version. As a consequence, nicotine delivery per puff approximates the American original. Notably, this is not associated with an increased generation of carbonyl compounds. Our data suggest a similar addictiveness of the enhanced European version and the original American product. Electronic supplementary material The online version of this article (10.1007/s00204-020-02716-3) contains supplementary material, which is available to authorized users.

Oberflachennahes Grundwasser unterliegt unterschiedlich starken Einflussen durch Oberflachengewasser. Dies konnen z. B. Fliesgewasser oder naturliche und kunstliche Seen wie etwa Baggerseen sein. Die Starke dieser Einflusse kann haufig mittels hydrologischer oder hydrochemischer Methoden aufgezeigt werden. Bislang ist unklar, ob im Bereich von Baggerseen – an denen die Grundwasseroberflache ungeschutzt frei liegt – eine Beeinflussung des Grundwassers auch anhand der Zusammensetzung der Lebensgemeinschaften sowie ihrer Besiedlungsdichten im Untergrund nachgewiesen werden kann. Vor diesem Hintergrund wurden im Jahr 2009 am Burkheimer Baggersee, zwischen Kaiserstuhl und Rhein gelegen, insgesamt 14 Grundwassermessstellen drei- bis viermal hydrochemisch und faunistisch untersucht. Mithilfe der Grundwasserfauna konnten hydrogeologische Muster im Umfeld des Baggersees nachgewiesen werden. Uber vier verschiedenartige faunistische Gruppen spiegelt sich die komplexe Hydrogeologie im Untersuchungsgebiet wider. Allerdings uberlagern die ortlichen hydrologischen Austauschprozesse mogliche Effekte des Baggersees auf das Grundwasser im Seeabstrombereich. Die faunistischen Gruppen umfassen „Gestresste Messstellen“ mit einer sehr verarmten Fauna, „Alluviale Messstellen“ mit einer artenreichen Oberflachenwassereinfluss anzeigenden Fauna, „Aufsteigendes Grundwasser“ mit einer individuen- und artenreichen Grundwasserfauna und „Rhein“, eine einzelne in Rheinnahe gelegene Messstelle, mit einer sehr stabilen, arten- und individuenarmen Grundwasserfauna. Ahnliche Einteilungen wurden auch in anderen Studien gefunden. Die Ergebnisse weisen darauf hin, dass hydrologische Austauschprozesse anhand der Fauna indiziert werden konnen. Ein direkter Nachweis von Baggerseeeffekten auf die Grundwasserfauna konnte in diesem Fall nicht erbracht werden.

In recent years the number of waterpipe smokers has increased substantially worldwide. Here we report on the concentrations of tobacco-specific nitrosamines (TSNAs) and polycyclic aromatic hydrocarbons (PAHs) in waterpipe smoke and the analysis of selected biomarkers indicative for the body burden in waterpipe users. We further identify high amounts of unburned humectants (glycerol and propylene glycol) in the waterpipe smoke as main part of the so-called "tar" fraction. These results give cause for serious concern. For standardization we applied a machine smoking protocol. Smoke was collected on glass fiber filters and analyzed for nicotine, water, humectants, TSNAs, and PAHs. In addition, we determined carbon monoxide and found high amounts in the smoke being causative for high levels of carboxyhemoglobin (COHb) in the blood of smokers. In comparison to the reference cigarette 3R4F, the nicotine contents were 10-times higher, but TSNA levels were found lower in waterpipe smoke. This finding explained the low levels of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol detected in the urine of waterpipe smokers. Finally, the levels of benzo[a]pyrene were three times higher in waterpipe smoke compared to the reference cigarette. Altogether, the data presented in this study point to the health hazards associated with the consumption of waterpipes.

Im Rahmen eines Pilotprogramms wurden in Rheinland-Pfalz funf Standorte mit Altlasten unterschiedlicher Herkunft auf das Auftreten und die Verteilung von Grundwassermeiofauna untersucht. Ziel dieser Vorstudie war es, erste Daten zur Verteilung der Grundwassermeiofauna in Altlaststandorten zu sammeln. Die Ergebnisse eines Standortes, hier bezeichnet als militarische Altlastflache C, werden im Detail vorgestellt. Trotz des vorlaufigen Charakters der Ergebnisse konnten fur einzelne Organismengruppen deutliche Verteilungsmuster gefunden werden. Wahrend die Crustacea (Krebstiere) mit LCKW (leichtfluchtige chlorierte Kohlenwasserstoffe) belastete Bereiche mieden, traten v. a. Nematoda und Oligochaeta flachendeckend und teilweise in hohen Abundanzen in allen untersuchten Bereichen auf. Diese beobachteten Verteilungen scheinen nicht nur arten- oder taxaabhangig zu sein, sondern moglicherweise auch abhangig von der Art des Schadstoffs. Langfristig ist anzustreben, die Grundwassermeiofauna auf ihre Eignung als Bioindikator zu testen. Bisher praktizierten physikochemischen Analysemethoden soll damit ein kostengunstiges, faunistisch begrundetes Monitoringsystem beigestellt werden, wie es sich in Oberflachengewassern seit Jahrzehnten bewahrt hat.

Medicinal plants are an important element of Ethiopian traditional medicine. This questionnaire survey examined the extent and type of medicinal plants used in self-care by rural Ethiopian community. Six hundred mothers were interviewed using a semi-structured questionnaire. The prevalence of the use of herbal drugs in self-care was found to be 12.5%. Twenty-five plant species belonging to 21 families were reported, each with local names, methods of preparation and parts used. This study showed that self-care using medicinal plants is a major part of health care options in Butajira community.

Background Electronic cigarettes (e-cigarettes) are advertised to tobacco users as a tool to decrease cigarette consumption and to reduce toxic exposure associated with conventional tobacco smoking. Little is known about the compounds contained in such products, their exposure and long-term health effects. Methods NMR spectroscopy was used to ascertain the content of several constituents of e-cigarette liquids including nicotine, solvents and some bioactive flavour compounds. Risk assessment was based on probabilistic exposure estimation and comparison with toxicological thresholds using the margin of exposure (MOE) approach. Results In 54 samples of e-cigarette liquids, the average nicotine content was 11mg/ml. Only 18 from 23 samples were confirmed as nicotine-free samples and in one e-cigarette liquid nicotine was not detected while being declared on the labelling. Major compounds of e-cigarette liquids include glycerol (average 37g/100g), propylene glycol (average 57g/100g) and ethylene glycol (average 10g/100g). Furthermore, 1,3-propanediol, thujone and ethyl vanillin were detected in some samples. The average exposure for daily users was estimated as 0.38mg/kg bw/day for nicotine, 8.9mg/kg bw/day for glycerol, 14.5mg/kg bw/day for 1,2-propanediol, 2.1mg/kg bw/day for ethylene glycol, and below 0.2mg/kg bw/day for the other compounds. The MOE was below 0.1 for nicotine, but all other compounds did not reach MOE values below 100 except ethylene glycol and 1,2-propanediol. Conclusions NMR spectroscopy is a useful and rapid method to simultaneously detect several ingredients in e-cigarette liquids. From all compounds tested, only nicotine may reach exposures that fall into a high risk category with MOE

Das Grundwasser ist von einer artenreichen, hochangepasten Tierwelt besiedelt, die zur Offenhaltung der Porenraume beitragt und die Selbstreinigungskraft der Grundwasserleiter fordert. Grundwasserabsenkungen und Schadstoffeintrage gefahrden diesen unterirdischen Lebensraum zunehmend. Die Auswirkungen stofflicher Eintrage auf die Grundwasserfauna sind noch unklar. Bei Grundwasserabsenkungen oder zustromendem Oberflachenwasser verandern sich die Lebensgemeinschaften dagegen in charakteristischer Weise, indem Grundwasserarten durch grundwasserfremde Tiere verdrangt werden. Damit erscheint eine faunistisch begrundete Eingriffsbewertung, die fur den Grundwasserraum bislang nicht stattfindet, moglich. Die Entwicklung geeigneter Standards fur ein faunistisch begrundetes Biomonitoring ist anzustreben.

Electronic (e-)cigarettes have emerged in recent years as putative alternative to conventional tobacco cigarettes. These products do not contain typical carcinogens that are present in tobacco smoke, due to the lack of combustion. However, besides nicotine, hazards can also arise from other constituents of liquids, such as solvents, flavors, additives and contaminants. In this study, we have analyzed 28 liquids of seven manufacturers purchased in Germany. We confirm the presence of a wide range of flavors to enhance palatability. Although glycerol and propylene glycol were detected in all samples, these solvents had been replaced by ethylene glycol as dominant compound in five products. Ethylene glycol is associated with markedly enhanced toxicological hazards when compared to conventionally used glycerol and propylene glycol. Additional additives, such as coumarin and acetamide, that raise concerns for human health were detected in certain samples. Ten out of 28 products had been declared “free-of-nicotine” by the manufacturer. Among these ten, seven liquids were identified containing nicotine in the range of 0.1–15 µg/ml. This suggests that “carry over” of ingredients may occur during the production of cartridges. We have further analyzed the formation of carbonylic compounds in one widely distributed nicotine-free brand. Significant amounts of formaldehyde, acetaldehyde and propionaldehyde were only found at 150 °C by headspace GC–MS analysis. In addition, an enhanced formation of aldehydes was found in defined puff fractions, using an adopted machine smoking protocol. However, this effect was delayed and only observed during the last third of the smoking procedure. In the emissions of these fractions, which represent up to 40 % of total vapor volume, similar levels of formaldehyde were detected when compared to conventional tobacco cigarettes. By contrast, carbonylic compounds were hardly detectable in earlier collected fractions. Our data demonstrate the necessity of standardized machine smoking protocols to reliably address putative risks of e-cigarettes for consumers.

The presence of C-peptide, proinsulin, insulin-A-chain, and glicentin in human fetal pancreatic cells by using the PAP-technique was investigated and the results obtained compared with the occurrence of insulin or glucagon immunoreactive cells. In pancreatic sections obtained from 10 weeks old human fetuses we could identify cells reacting with antibodies directed against C-peptide, proinsulin, and insulin-A-chain. The majority of the cells were found in the duct epithelium and their number increased from the 10th to 14th week forming clusters near the ducts. The number and localization of the cells correspond exactly to the insulin positive cells. The presence of proinsulin and insulin-A-chains is a further proof of biological activity already in an early step of fetal development. The presence of glicentin-positive cells in the 10th week of gestational age as well as cells reacting with glucagon antibodies provide evidence for active glucagon biosynthesis. The number of these cells increased markedly in the 14th week of gestational age.

Objective To study the utilization patterns of herbal drug use in urban Ethiopia. Methods A cross-sectional community-based survey was conducted in Addis Ababa capital city of Ethiopia using a pre-tested semi-structured questionnaire. The questionnaire was administered to 600 heads of households largely mothers selected using a multi-stage systematic random sampling technique where the final sampling units were households. Results The prevalence of herbal drugs use was found to be 37%. The main reasons given for choosing herbal medicine as the first line medication option were: dissatisfaction with the services of modern health institutions due to their time consuming nature cost considerations and perceived efficacy. Conclusion This study showed that in spite of the geographic accessibility of modern health institutions in urban areas the use of traditional medicine particularly herbal drugs remains a major form of health care option. Hence health planners should give appropriate consideration to this sector. (authors)

Key informant interviews of herbalists were conducted to document the traditional management of malaria in Ethiopia. The perceptions of the cause and symptoms of malaria, the use of plants, their preparation and administration were recorded. Interviews were performed in rural Butajira and Addis Ababa (the main city). The result showed that 33 (75%) of the interviewed healers treat malaria using herbal drugs. Sixteen plants were reported to have been used of which eight were used as a single remedy and the rest as composite remedies with other plants. The ethnopharmacological data generated in this study on antimalarial plants is useful for further evaluations of the traditional claims of antimalarial plants in Ethiopia.

Objective: To assess herbalist’s mode of service delivery and describe their traditional pharmaceutical practices. Methods: In-depth interviews of herbalists were conducted in Addis Ababa and Butajira, using a semi-structured questionnaire. Results: The mean age of the healers was 53.7 and most of the healers practised traditional medicine on part-time basis. The average number of patients seen per week by the healers was 7. Most of the healers do not have fixed payment rate for their services. The analysis of traditional prescriptions revealed that the predominant dosage forms were liquid preparations and the average number of plants per prescription was 1.16. Conclusions: Healers treat a wide range of health problems using medicinal plants in various dosage forms. In the process of evaluation and standardisation of these dosage forms, formulations tested should be made in accordance with the method used traditionally. [Ethiop.J.Health Dev. 2002;16(2):191-197]

The article contains sections titled: 1. Introduction 2. Companies, Markets, and Products 3. Legal Requirements 3.1. General 3.2. Definitions 3.3. Requirements Relating to the Development of Drugs 3.4. Marketing Approval 3.5. Requirements for the Manufacture and Quality Control of Drugs 3.6. Requirements for the Placing of a Drug on the Market 3.7. Drug Liability 3.8. International Non-Proprietary Names (INN) 4. Drug Testing 4.1. Preclinical Testing 4.1.1. Introduction 4.1.2. Animal Experiments 4.1.3. Pharmacological Testing 4.1.4. Toxicological Testing 4.2. Clinical Trials 4.2.1. Phases of Clinical Drug Development 4.2.2. Methods for Proving Effectiveness 4.2.3. Adverse Drug Reactions 4.2.4. Good Clinical Practice 4.2.5. Clinical Application Dossier 4.3. Quality Control of Pharmaceutical Products 4.3.1. Manufacturing of Drug Substances - Test of Starting Materials 4.3.2. Control of Drug Substances: Impurities 4.3.3. Control of Drug Products: Impurities 4.3.4. Validation of Analytical Procedures 4.3.5. Process Validation and Qualification 4.3.6. Batch Release 4.3.7. Stability Testing 4.3.8. Documentation 4.3.9. Variations - Changes 4.3.10. Change Control 4.3.11. Compliance 4.3.12. Changes Requiring New Applications - Line Extension 4.3.13. Inspections 4.3.14. The Mutual Recognition Agreement (MRA) 4.3.15. Pharmaceutical Inspection Convention (PIC) 4.3.16. Pharmaceutical Inspection Cooperation Scheme (PIC/S) 4.3.17. Pharmacopeias 4.3.18. The EP Certificate of Suitability

The cerebral availability of the peripherally and centrally acting catechol-O-methyltransferase (COMT) inhibitor tolcapone is not known in humans. Therefore, we determined the concentration of tolcapone in cerebrospinal fluid (CSF) of 12 parkinsonian subjects 1-4 h after oral application of 200 mg of the drug. The mean concentration was 56.4+/-35.5 nmol/l (mean +/- SD). This concentration was calculated to cause 75.2+/-15% (mean +/- SD) inhibition of COMT in CSF. Thus, tolcapone efficiently inhibits COMT after crossing the blood-brain barrier in humans.

By means of collagenase digestion and the Ficoll gradient separation technique, viable islets of Langerhans were isolated from canine pancreas. These islets were transplanted into the livers of diabetic dogs. Experimental diabetes was induced by subtotal pancreatectomy and two injections of 25 mg streptozotocin/kg body wt. Five recipients received islets from weakly histocompatible donors and were immunosuppressed by administration of azathioprine and anti-thymocyte serum. Diabetes was ameliorated over a period of 1 year. Glucose tolerance test curves and immunoreactive insulin concentrations in the portal and superior vena cava were significantly impaired in comparison to the diabetic control dogs. No signs of portal hypertension or of disturbances of liver function were observed in recipient dogs during the duration of the experiment.

DNA synthesis and labelling index of isolated neonatal rat islets were investigated during a 4 to 5 culture period in TCM 199 (10 mmol/l glucose) under selected conditions, as change of serum concentration in the medium or addition of a proliferation stimulating fraction. Additionally it should be proved whether the DNA-synthesis of pancreatic islets, measured as [3H]-thymidine incorporation, is representative for the amount of cells during the S-phase (= "growth fraction"). There is a correlation between the incorporation of [3H]-thymidine into the TCA-precipitate and the labelling index of islets determined on HE-stained radioautographs. For this reason and because of being less time-consuming, the measurement of DNA synthesis is a suitable screening method for selection of factors increasing the growth fraction of pancreatic beta-cells. Only the addition of FGF-S3 (growth stimulating raw prepared isolated from bovine brain) during culture caused a significant increase of DNA synthesis and labelling index of the islets. The labelling index of radioautographs stained by immunofluorescence method for insulin did not differ significantly from that determined at HE-stained radioautographs. Insulin secretion and content of the islets were not influenced by the addition of FGF-S3.

The ether soluble fraction of atmospheric aerosol particles was separated into the following groups of compounds: organic acids and phenols, organic bases, aliphatic hydrocarbons, aromatic hydrocarbons and neutral compounds. These groups in turn were analyzed for individual constituents. Aerosol samples were collected from six different geographic regions: three over the European continent with different degrees of air pollution and three from Atlantic air masses. In all cases the organic fraction of atmospheric aerosol particles had a very complex composition. However, the relative composition with respect to the main groups of organic compounds remained fairly constant in all areas sampled. This indicates either a common origin or formative processes throughout the atmosphere resulting in a similar net product.

The effect of acetylsalicylic acid (aspirin) on the ultrastructure of the gastric and jejunal mucosa was investigated in patients undergoing gastric surgery and in guinea pigs. The drug caused various degrees of damage to the surface mucous cells in both species perceptible as general signs of cytolysis in situ or as desquamation. In patients pretreated with aspirin, an increase of secondary lysosomes was noted in the gastric parietal cells but not in the animals. In the intestinal epithelial cells of both species there was a marked increase of secondary lysosomes, probably representing autophagolysosomes. The simultaneous increase of multi vesicular bodies and the occurrence of transitional stages between the two organoids suggest a functional interrelationship. Since no specific alteration of any cellular organoid was detected, the drug-induced injury is assumed to occur on a molecular level in the cytoplasm. It is concluded that the intracellular concentrations of aspirin in gastrointestinal mucosal cells during absorption cause cellular injury that can usually be restored by cellular repair mechanisms but that high drug concentrations may lead to irreversible cell damage.

The regional and cellular distribution of insulin-like immunoreactivity throughout the CNS of three rodent species were investigated using an immunofluorescence technique. No principal differences in the content and distribution of insulin-like material were revealed between lean animals and mice suffering from a genetically determined diabetes mellitus.

Summary Using an indirect fluorescence technique and the unlabelled enzyme technique of Sternberger (PAP-techniques) we were able to demonstrate a widespread distribution of insulin, C-peptide and glucagon throughout the human brain.

Investigation of glucagon secretion in isolated Wistar rat islets was carried out to elucidate further the regulatory function of glucose and arginine on pancreatic A-cells. The suppressive effect of D -glucose could also be demonstrated with L -glucose, D -mannose, D -fructose, D -galactose, D -glyceraldehyde and DL -dihyroxyacetone, but not in the presence of 3-O-methylglucose or mannitol. Sugars other than D -glucose inhibited glucagon secretion only at much higher concentrations than those at which D -glucose was effective. Furthermore, although 7.5 mM D -glucose caused up to 80% inhibition, the effects of other sugars appeared to level off at only 50–60% inhibition. The inhibitory action of D -glucose or D -glyceraldehyde on glucagon secretion could not be overcome by L -arginine, but 3-O-methylglucose, mannoheptulose, 2-deoxy- D -glucose, iodoacetamide, theophylline, epinephrine and acetylcholine were effective. The insulin secretion in response to glucose was inhibited by the metabolic inhibitors used, whereas the B-cell response in the presence of glyceraldehyde was diminished by iodoacetamide only. Like D -glucose, a variety of other sugars markedly reduced the stimulatory effect of L -arginine in glucagon release. The results show that the suppression of glucagon secretion is not specific for D -glucose and not strongly connected on a stimulated insulin secretion.

By means of collagenase digestion and the Ficoll gradient separation technique, viable islets of Langerhans could be isolated from dog pancreata. The isolated islets were capable of secreting insulin after glucose stimulation. These islets of Langerhans were transplanted into the livers of diabetic dogs. We transplanted islets isolated from I donor pancreas for 1 kg body wt of the recipients. The dogs were made diabetic by subtotal pancreatectomy (80%) and two injections of 25 mg streptozotocin/kg body wt. In our experiments, we selected donor-recipient pairs by means of the mixed lymphocyte reaction macrophage electrophoretic migration inhibition (MLR-EM) test. In the group with a depression in the MLR-EM test of more than 15% (strong histoincompatibility), the mean survival time of the transplanted dogs was 46 ± 16 days. Another group of recipients with a depression of macrophage migration of less than 8% (weak histocompatibility) had a mean survival time of 135 ± 49 days after intraportal islet transplantation, and the blood glucose values could be normalized in this group for a period of 70 days. We found significant differences between both the groups in the glucose tolerance tests and in the IRI concentrations in the portal vein and in the vena cava superior. In the recipients, which received weakly histoincompatible islets, the IRI concentration in the superior vena cava was 64% of the normal value in the vena cava superior 4 weeks after intrahepatic islet transplantation. By means of the MLR-EM test, we were able to correlate inhibition with signs of rejection of the transplanted islets. Our experiments demonstrated that an allogeneic islet transplantation in diabetic dogs across a weakly histocompatible barrier can improve the results in comparison to the islet transplantation across a strongly histocompatible barrier. However, this typing maneuver alone is not able to prevent the islet rejection.

Summary Using immunofluorescence technique a positive reaction to insulin antiserum could be revealed in different parts of the CNS of Wistar rats and sand rats. The functional concept that nervous tissue is insulin-insensitive was called in question by investigations showing an influence of insulin on blood plasma glucose levels after an application of the hormone to the CNS ( Szabo and Szabo 1972). Recently, the presence of specific insulin receptors in the brain was demonstrated by radiochemical ( Havkankova et al. 1978) and immunocytochemical ( Pansky and Hatfield 1978) means. No data, however, are yet available concerning the occurrence of the hormone itself in the CNS. We present evidence for the existence in the rat CNS of a substance giving an immunological reaction with insulin-antiserum.

Glucose stimulates the uptake of 45Ca into (3-cell-rich pancreatic islets isolated from ob/ob-mice. The distribution of the incorporated radioactivity was analysed by labelling the organelles with 45Ca in their cellular environment. The radioactive content of the organelles was measured after homogenization and fractionation of the islets under conditions preventing 45Ca redistribution. The 45Ca taken up in response to glucose appeared essentially in the secretory granule fraction and in that enriched in mitochondria. Modification of the 45Ca loading procedure, involving reduction of the oxygen tension and incubation volume, resulted in the disappearance of the glucose effect on the mitochondrial fraction whereas part of the stimulatory effect on the secretory granules persisted. Buffering of calcium by the secretory granules and mitochondria may be important for regulating the cytoplasmic Ca2+ involved in stimulus-secretion coupling.

Using the PAP technique, we investigated the presence of neuron-specific enolase in the human fetal pancreas of 10, 12, and 14 weeks of gestational age. Neuron-specific enolase is present in the islet cells in the 10th week. Positive cells are situated mainly in duct epithelium. The number of cells with a positive reaction increases from the 12th to the 14th week. In the 14th week, they are clustered either near the ducts or between the acini. The numbers and localizations of the cells correspond to those obtained in previous studies with 4 basic islet cell types in the same material. The present results are a further proof that islet cells are biologically active during early fetal development.

Summary The hypothalamic and extrahypothalamic distribution of somatostatin-like immunoreactivity (SLI) was investigated in fed adult sand rats ( Psammomys obesus ) of both sexes using the immunofluorescence technique. Blood glucose and insulin concentrations were determined in these animals prior to decapitation. In a blind study, the amount of immunofluorescence of certain CNS areas and the glucose: Insulin ratio were compared and found to be connected: High amounts of SLI were detected in the dorsal hippocampus, in some hypothalamic nuclei and the median eminence of rats displaying low glucose levels. Sand rats with high blood glucose values did not show SLI in the hippocampal formation and the immunofluorescence of the circumventricular (hypothalamic) regions and the Emmentia mediana was drastically reduced. A possible correlation of SLI with insulin concentrations in the blood could not be revealed. The data obtained are discussed as a possible expression of a CNS influence on glucoregulation in this species.

Summary C-peptide/C-peptide-like immunoreactivity was shown to be present in the cytoplasm of the soma and the proximal part of apical dendrites of some pyramidal cells in the Neocortex (Gyrus precentralis) and Hippocampus of man. C-peptide (connecting peptide) is a metabolic product in insulin biosynthesis and its localization in neurons is a proof for extrapancreating insulin production.

Summary Glukagon-like immunoreactivity was demonstrated in different parts of rat and sand rat central nervous system by the indirect immunofluorescence method. In hyperglycemic animals the level of immunoreactive material was reduced to a great extent.

Twenty partially inbred German shepherd dogs were made diabetic by intravenous administration of streptozotocin (25 mg/kg) 1 and 3 days after partial pancreatectomy. Ten diabetic dogs received intraportal transplants of allogeneic islets of Langerhans isolated by collagenase digestion and Ficon gradient separation. After transplantation the mean fasting serum glucose level fell from 368 ± 74 to 108 ± 52 mg/dl. Normal glycemia was maintained for at least 3 weeks before rejection occurred. The mean survival time of the 10 recipients was 76 ± 30 days, while the 10 diabetic control dogs had a mean survival time of 30 ± 7 days. Intravenous glucose tolerance test curves were clearly better in recipient dogs than in the diabetic control dogs for at least 4 weeks after islet transplantation. Concentrations of immunoreactive insulin (IRI) in the portal vein in the superior vena cava were also significantly higher than in the diabetic control dogs 4 weeks after islet transplantation. The mean peak concentration of IRI in the superior vena cava of transplanted dogs after glucose administration was higher than that in the portal vein, indicating that the transplanted islets secreted insulin in response to glucose stimulation. Portal hypertension or disturbance of liver function did not occur after transplantation of isolated islets. These results show that the intrahepatic site is appropriate for transplantation of isolated islets in a large animal model of diabetes, and provide a basis for future application in man.

The effect of cyclic AMP on calcium movements in the pancreatic beta-cell was evaluated using an experimental approach based on in situ labelling of intracellular organelles of ob/ob-mouse islets with 45Ca. Whereas the glucose-stimulated 14Ca incorporation by mitochondria and secretory granules was increased under a condition known to reduce cyclic AMP (starvation), raised levels of this nucleotide (addition of 3-isobutyl-1-methylxanthine or N6,O2'-dibutyryl adenosine 3',5'-cyclic monophosphate) reduced the mitochondrial accumulation of 45Ca. Conditions with increased cyclic AMP were associated with a stimulated efflux of 45Ca from the secretory granules but not from the mitochondria. The microsomal fraction differed from both the mitochondrial and secretory granule fractions by accumulating more 45Ca after the addition of 3-isobutyl-1-methylxanthine. The results suggest that cyclic AMP potentiates glucose-stimulaated insulin release by increasing cytoplasmic Ca2+ at the expense of the calcium taken up by the organelles of the pancreatic beta-cells.

Summary The presence of glucagon-like immunoreactivity in nerve cells of different parts of the human brain was demonstrated by the indirect immunofluorescence technique. A bright fluorescent reaction was observed in the pyramidal cells of lamina V of the Neocortex. Less prominent concentrations of the glucagon-like material were detected in a few pyramidal cells of the Hippocampus and in some neurons of the Presubiculum and Subiculum. Within the Corpus amygdaloi-deum, only a few magnocellular neurons showed a positive reaction. The Hypothalamus was evidenced by a moderate, but widely distributed, reaction in magnocellular and medium-sized nerve cells in different nuclei (especially Nuc. ventromedialis and Nuc. arcuatus). A strong immunofluorescence was localized to some neurocytes in the Nuc. amibigus, and Nuc. n. hypoglossi. The Purkinje cells of the cerebellar cortex were free from immunoreactive material, but fluorescence occurred in some very small nerve cells of the Cerebellum (probably granular cells). A dependence of the strength of immunofluorescence of the time delay between autopsy and death is shown.