Enteral histaminosis: Clinical implications.

There is increasing evidence that enteral histaminosis is a major cause of food intolerance resulting from dysfunctional metabolism of endogenous histamine in certain food stuffs. However, this phenomenon has been poorly characterised and, due to the lack of epidemiological data, the existence of this condition has been underestimated, which may lead to incorrect diagnosis. This short commentary highlights a stricter regimen of diagnostic procedure in order to take into account the many causes of food intolerance. The underlying mechanisms ascribed particularly to non-immunologically food reactions require more rigorous research and further work is vital.

[Intrafemoral pressure measurement in different cement removal procedures during hip prosthesis replacement operations--experimental study with cadaver femora]. / Intrafemorale Druckmessung bei unterschiedlichen Zemententfernungsverfahren bei Hüftprothesenschaftwechseloperationen--Experimentelle Studie an Leichenfemora.

During primary hip arthroplasty an increase in intramedullary pressure (IMP) of up to 1000 mm Hg can be observed. As a result of this increased intrafemoral pressure, intramedullary constituents can pass into the venous circulation creating a risk of fat embolism syndrome (FES). In the present experimental study on 9 femora obtained from human corpses, we investigated the question as to whether various methods of cement removal during total hip revision arthroplasty are also associated with increased intramedullary pressure and a risk of FES. The IMP was recorded with a standardized experimental set-up during removal of cement from the proximal and distal regions, including removal of the cement "tip" and the intramedullary plug. The methods employed for this purpose included the osteotome and mallet, a compressed air powered chisel, and a modified intracorporal lithotripter. All the methods induced fluctuations in the IMP the highest values being recorded for the conventional method using the osteotome and mallet (45 mm Hg) and the lowest values for the intracorporeal lithotripter (7.5 mm Hg). Working on the distal cement caused higher fluctuations in comparison with the proximal region. The study failed to reveal any increase in mean IMP, and all measured values were in the low pressure range (considerably below 150 mm Hg). While there seems to be no apparent risk of an FES developing during removal of cement, careless manipulation of the distal cement plug may result in higher intrafemoral pressures--above 150 mm Hg--thus increasing the risk of a fat embolism syndrome.

Zinc metabolism in fasted rats.

The effects of short-term starvation on serum and tissue levels of zinc, metallothionein (MT), and the activity of alkaline phosphatase (EC 3.1.3.1, ALP) were investigated with 6-month-old rats. The rats were fed a diet with adequate zinc (92mg/kg of Zn, 1.12% phytic acid) before they were starved for 0h (control), 12h, 24h, and 36h and then killed by decapitation. Fasting was accompanied by typical changes in serum parameters such as reduced glucose and protein concentrations, elevated ketogenesis, and a rapid breakdown of liver glycogen. Fasting did not alter serum zinc levels, but it did lead to a significant elevation in the percent of unsaturated serum-zinc binding capacity. Liver concentrations of zinc and MT, based both on fresh and dry weight, were increased throughout starvation. However, total liver zinc was reduced by up to 23% in response to fasting and total liver MT was slightly elevated. The increased concentrations of liver zinc and MT are, therefore, mainly a consequence of reduced liver weight. A part of the liver zinc, however, was bound to newly synthesized MT to prevent greater zinc loss. Starvation evoked no altered mucosa MT levels. Changes in kidney zinc and kidney medulla MT caused by starvation were small and not significant. In contrast to this observation some variation of kidney cortex MT was apparent. Starvation produced a permanent reduction of the serum and intestinal activity of ALP. In the liver and the medulla of the kidneys no significant differences of ALP activity could be observed. However, kidney cortex ALP was induced after 36h of fasting.(ABSTRACT TRUNCATED AT 250 WORDS)

Short-term memory performance with magnetic stimulation of the motor cortex.

Whether transcranial magnetic stimulation of the motor cortex has an influence on memory was investigated. In a first experiment with 21 healthy volunteers six pronounceable nonsense words were visually presented, immediately followed by a magnetic stimulus. There were three blocks of stimulation with field intensities of 60, 80 and 100% (referring to a maximal intensity of 2 Tesla), each block comprising six magnetic stimuli and six nonsense words. After each block there was a free recall test and at the end another free recall trial as well as a multiple-choice recognition test for all 18 words. Eighteen subjects served as controls, undergoing the same procedure, except that the field intensity was zero. A significant but small reduction of short-term memory performance was observed only for 100% field intensity. In a second experiment with 16 subjects who had not participated in experiment I, the effect of 100% intensity cortical magnetic stimulation was compared with a control stimulation over the cervical spine. There was no difference in free recall or in the multiple-choice test between the sites of stimulation, suggesting that the difference in the 100% intensity block in experiment I was not due to a specific cortical effect of the magnetic field on memory function. With respect to the effect on memory functions, transcranial magnetic stimulation of the motor cortex is thought to be a safe method.