Antidiabetic medications in overdose: a comparison of the inquiries made to a regional poisons unit regarding original sulfonylureas, biguanides and insulin.

OBJECTIVE: The drugs most commonly used to treat diabetes mellitus are sulfonylureas, biguanides and insulin. The most serious effects seen in overdose with these agents are hypoglycemia or lactic acidosis which may be fatal or cause cerebral defects. The present investigation analyzes inquiries made to a regional poisons unit involving overdoses with sulfonylureas, biguanides and insulin. PATIENTS AND METHODS: A total of 218,070 made inquiries between 1995 and 2004 were evaluated. The inquiries were received by telephone and a standardized questionnaire was sent subsequently to the physicians calling for follow-up information. The cases were analyzed with regard to gender, age, etiology, symptoms and clinical outcome. RESULTS: 263 inquiries concerning sulfonylureas (48.3% female, 49.4% male, 2.3% sex unknown, average age 39.1 +/- 26.8 years), 172 concerning biguanides (60.5% female, 37.2% male, 2.3% sex unknown, average age 41.5 +/- 24.1 years), and 191 concerning insulin (53.9% female, 41.9% male, 4.2% sex unknown, average age 44.6 +/- 16.7) were made. In cases involving sulfonylureas, the etiology was deliberate self-poisoning in 62.7% and accidental in 31.9% (biguanides 60.5% and 29.1%, insulin 85.3% and 9.4%). Using the Poisoning Severity Score, no symptoms were observed in 41.4% of the patients with sulfonylurea overdose (biguanides 40.1%, insulin 22.5%), minor symptoms in 37.6% (biguanides 32.6%, insulin 33.5%), major symptoms in 14.4% (biguanides 13.4%, insulin 26.2%) and serious symptoms in 4.6% (biguanides 12.2%, insulin 14.7%). Returned questionnaires reporting clinical outcomes showed that a full recovery occurred in most patients (sulfonylureas 97.4%, biguanides 93.0%, insulin 94.4%), cerebral defects persisted in 1.8% of the cases involving sulfonylureas (biguanides 1.5%, insulin 2.4%), and that 0.9% of the patients with sulfonylurea overdose died (biguanides 6.1%, insulin 3.6%). CONCLUSIONS: Sulfonylureas were the most frequently observed medication in cases of overdose with antidiabetic agents. Insulin overdose caused the highest number of major and serious symptoms. Overdose with biguanides led to the most deaths.

Enterococcus faecalis gene transfer under natural conditions in municipal sewage water treatment plants.

The ability of Enterococcus faecalis to transfer various genetic elements under natural conditions was tested in two municipal sewage water treatment plants. Experiments in activated sludge basins of the plants were performed in a microcosm which allowed us to work under sterile conditions; experiments in anoxic sludge digestors were performed in dialysis bags. We used the following naturally occurring genetic elements: pAD1 and pIP1017 (two so-called sex pheromone plasmids with restricted host ranges, which are transferred at high rates under laboratory conditions); pIP501 (a resistance plasmid possessing a broad host range for gram-positive bacteria, which is transferred at low rates under laboratory conditions); and Tn916 (a conjugative transposon which is transferred under laboratory conditions at low rates to gram-positive bacteria and at very low rates to gram-negative bacteria). The transfer rate between different strains of E. faecalis under natural conditions was, compared to that under laboratory conditions, at least 10(5)-fold lower for the sex pheromone plasmids, at least 100-fold lower for pIP501, and at least 10-fold lower for Tn916. In no case was transfer from E. faecalis to another bacterial species detected. By determining the dependence of transfer rates for pIP1017 on bacterial concentration and extrapolating to actual concentrations in the sewage water treatment plant, we calculated that the maximum number of transfer events for the sex pheromone plasmids between different strains of E. faecalis in the municipal sewage water treatment plant of the city of Regensburg ranged from 10(5) to 10(8) events per 4 h, indicating that gene transfer should take place under natural conditions.

DNA measurements and ploidy determination of developmental stages in the life cycles of Theileria annulata and T. parva.

The relative DNA levels of different developmental stages of Theileria annulata and T. parva in the cow and the tick were measured by the cytophotometric DNA technique using the fluorochrome Hoechst 33258 as a staining dye. The results revealed that sporozoites, merozoites, gamonts, and gametes were haploid, whereas multinucleated intralymphocytic schizonts were polyploid. No difference was observed between T. parva and T. annulata in these stages. For both Theileria species, the DNA measurements revealed that fusion of gametes occurred in the gut of the final host, thus providing evidence of sexual reproduction. However, differences were observed between the two parasites in the tick. Whereas T. parva zygotes underwent a two-step meiotic division, a comparable reduction division could not be unequivocally detected in T. annulata. Differences could also be detected in the further development of kinetes, indicating that Theileria species are not characterized by only one life cycle, which is specific for this genus.

DNA measurements reveal differences in the life cycles of Babesia bigemina and B. canis, two typical members of the genus Babesia.

The relative DNA levels of different developmental stages of Babesia bigemina and B. canis were measured by cytophotometry using the fluorochrome Hoechst 33258 as a staining dye. The DNA measurements provided direct proof of sexual reproduction, i.e., fusion of gametes resulting in the formation of zygotes followed by a meiotic division. Both Babesia species are considered to be typical members of the genus Babesia; however, the DNA measurements revealed important differences in the life cycle of these parasites, indicating that Babesia species are not characterized by a life cycle, which is specific for this genus.

Sexual cycle of Babesia divergens confirmed by DNA measurements.

The DNA content of the developmental stages within the life cycle of Babesia divergens was measured by means of fluorescence microscopy using the DNA-specific bisbenzimide Hoechst 33258. By comparing the mean relative fluorescence intensities, the assumption of sexual reproduction in the gut of the tick vector (Ixodes ricinus) was confirmed. However, no proof of a pre- or postzygotic meiosis was found.