Ciprofloxacin reduces the risk of hemolytic uremic syndrome in patients with Escherichia coli O104:H4-associated diarrhea.

BACKGROUND: Whether antibiotic treatment in patients with enterohemorrhagic Escherichia coli (EHEC)-associated diarrhea influences the risk of hemolytic uremic syndrome (HUS) has still to be elucidated. PATIENTS AND METHODS: During the EHEC epidemic which occurred in northern Germany in spring 2011, 24 patients with E. coli O104:H4 infection were treated at our hospitals, 19 of whom developed HUS. The use of antibiotics before and after the onset of HUS was documented, and the outcome in patients with and without antibiotic treatment was evaluated. RESULTS: Of the 24 patients with EHEC-associated diarrhea, seven received antibiotics before any signs of HUS were present (ciprofloxacin, cefotaxime, amoxicillin and/or metronidazole). Four of these seven patients (57 %) and 15 of the 17 patients (88 %) who were treated without antibiotics developed HUS (p = 0.12). Microbiological testing showed all E. coli O104:H4 to be extended-spectrum beta lactamase producers and thus susceptible only to fluoroquinolones, aminoglycosides and carbapenems. Two of the five patients (40 %) treated with ciprofloxacin and 17 of the 19 patients (89 %) treated without ciprofloxacin developed HUS (p = 0.043). CONCLUSION: In our E. coli O104:H4-infected patients, treatment of diarrhea with antibiotics did not increase the risk of HUS. Significantly fewer patients treated with ciprofloxacin developed HUS than patients who did not receive ciprofloxacin.

Long-distance navigation in the wandering desert spider Leucorchestris arenicola: can the slope of the dune surface provide a compass cue?

Males of the nocturnal spider Leucorchestris arenicola (Araneae: Sparassidae) wander long distances over seemingly featureless dune surfaces in the Namib Desert searching for females. The spiders live in burrows to which they return after nearly every such excursion. While the outward path of an excursion may be a meandering search, the return path is often a nearly straight line leading towards the burrow. This navigational behaviour resembles that of path integration known from other arthropods, though on a much larger scale (over tens to hundreds of meters). Theoretically, precise navigation by path integration over long distances requires an external compass in order to adjust for inevitable accumulation of navigational errors. As a first step towards identifying any nocturnal compass cues used by the male spiders, a method for detailed 3-D recordings of the spider's paths was developed. The 3-D reconstructions of the paths revealed details about the processes involved in the spiders' nocturnal way of navigation. Analyses of the reconstructed paths suggest that gravity (slope of the dune surface) is an unlikely parameter used in path integration by the L. arenicola spiders.

The influence of food supply on foraging behaviour in a desert spider.

We tested the alternative hypotheses that foraging effort will increase (energy maximizer model) or decrease (due to increased costs or risks) when food supply increased, using a Namib desert burrowing spider, Seothyra henscheli (Eresidae), which feeds mainly on ants. The web of S. henscheli has a simple geometrical configuration, comprising a horizontal mat on the sand surface, with a variable number of lobes lined with sticky silk. The sticky silk is renewed daily after being covered by wind-blown sand. In a field experiment, we supplemented the spiders' natural prey with one ant on each day that spiders had active webs and determined the response to an increase in prey. We compared the foraging activity and web geometry of prey-supplemented spiders to non-supplemented controls. We compared the same parameters in fooddeprived and supplemented spiders in captivity. The results support the "costs of foraging" hypothesis. Supplemented spiders reduced their foraging activity and web dimensions. They moulted at least once and grew rapidly, more than doubling their mass in 6 weeks. By contrast, food-deprived spiders increased foraging effort by enlarging the diameter of the capture web. We suggest that digestive constraints prevented supplemented spiders from fully utilizing the available prey. By reducing foraging activities on the surface, spiders in a prey-rich habitat can reduce the risk of predation. However, early maturation resulting from a higher growth rate provides no advantage to S. henscheli owing to the fact that the timing of mating and dispersal are fixed by climatic factors (wind and temperature). Instead, large female body size will increase fitness by increasing the investiment in young during the period of extended maternal care.

Foraging at the thermal limit: burrowing spiders (Seothyra, Eresidae) in the Namib desert dunes.

In the Namib Desert dunes, the web of Seothyra sp. (Eresidae) comprises sticky silk lining the edges of a horizontal mat on the sand surface. The spider sits in a silk-lined burrow attached to the mat. Arthropods become entangled in the sticky silk of the mat and are attacked and pulled into the burrow by the spider. We investigated the influence of sand surface temperature on the activity of spiders during the summer. We determined the range of thermal conditions encountered by spiders, their temperature tolerance and the influence of temperature on foraging activity and prey handling behavior. The environmental temperatures available to Seothyra vary from 17-33° C at the coolest time of day to 33-73° C at the hottest. When prevented from retreating into burrows, spiders showed signs of thermal stress at about 49° C, whereas unrestrained spiders continued to forage at web temperatures above 65° C by moving between the hot surface mat and the cooler burrow. Spiders responded quicker to prey stimuli during the hot hours of the day and completed prey capture sequences in significantly less time at surface temperatures above 49° C than below. Furthermore, captured arthropods succumbed more quickly at high surface temperatures. Our study supports the hypothesis that web design and thermoregulatory behaviors enable Seothyra to hunt under extreme thermal conditions.

[Nutrition-physiological properties of frying fats. 8. Hematological and blood-chemical studies]. / Uber die ernährungsphysiologischen Eigenschaften von Fritierfetten. 8. Mitteilung Hämatologische und blutchemische Untersuchungen

The hematological and chemical examination of the 3rd generation of rats fed soy bean oil used for fish frying showed not any abnormal data.

[Nutrition-physiological properties of frying fats. 9. Overfeeding of frying fats and the drug- and toxic-substance-detoxicating microsomal enzyme-system of the liver]. / Uber die ernährungsphysiologischen Eigenschaften von Fritierfetten. 9. Mitteilung Verfütterung von Fritierfetten und das Drogen und toxische Substanzen entgiftende mikrosomale Enzymsystem der Leber

Long-term feeding of frying oil to male rats increases significantly the activity of the drug and toxic substances metabolizing microsomal enzyme system. This effect was also seen in the females, but only statistically insignificant.

[Nutrition physiological aspects of deep frying fats. 7. Effect of deep frying fats on the lipid metabolism and the fatty acid composition of body lipids]. / Uber die ernälhrungsphysiologischen Eigenschaftern von Fritierfetten

In feeding experiments no differences could be observed when used frying fats were fed to rats in the same amount and over the same period if compared with the unheated fats (partially hardened groundnut oil, soyabean oil). In details we investigated: concentration of plasma lipids, including content of total cholesterol, electrophoresis of plasma lipoproteins, fatty acid composition of plasma lipids and of adipose tissue. Amount and composition of the unsaponifiable matter in heated and unheated fats as well as the content of polycyclic aromatic hydrocarbons were determined. In in-vitro experiments we investigated the effect of pancreas lipase on these fats.