Premature induction of hepatic tryptophan oxygenase

Subcutaneous administration of hydrocortisone acetate to the newborn rat produces a premature induction of hepatic tryptophan oxygenase consisting of a transient rise in activity 6–8 h after treatment, followed by a second sustained rise beginning 40 h later, which plateaus at 10 days of age. Cycloheximide treatment at the midpoint of this second elevation inhibits protein synthesis, but not tryptophan oxygenase activity. In older animals, cycloheximide treatment does both. Tryptophan administration at this midpoint rapidly elevates tryptophan oxygenase activity. This elevation can be partially blocked by treatment with actinomycin D within 1 h of tryptophan administration, but not thereafter. Actinomycin treatment is ineffective in blocking the tryptophan-induced rise in older animals. Administration of hydrocortisone acetate to 5- and 10-day-old pups leads to a more rapid and sustained rise in tryptophan oxygenase activity without appearance of a transient induction phase. Neither tryptophan alone, -aminolevulinic acid alone, nor tryptophan plus -aminolevulinic acid prematurely induces tryptophan oxygenase in newborn or 5-day-old rats.     

Urinary corticosterone levels in mice in response to intraperitoneal injections with saline

The concept of refinement is an important issue in the field of laboratory animal science. Refinement-based research aims to improve animal welfare, to increase the reliability of experimental outcome, and to diminish variation. In search of refinement of experimental techniques, this study investigated whether urinary corticosterone can be used as a noninvasive measure of acute stress in mice.     

Tissue banking in South Africa: a 19-year history

The establishment of a Tissue Bank and the science of Tissue Banking in South Africa started in the 1960s and is still developing. This article describes the development and growth of Tissue Banking in South Africa. The current emphasis is to supply viable bone products that have been produced under the best possible quality controlled circumstances; with the collaboration between different Organ Donation Organisations. Through collaboration, a dramatic increase in the number of donors was noted over the years. Concurrently, there was a dramatic increase in the usage of different allograft products and now necessitates the development of new graft materials for expanding patient options. As an ongoing concern, the Tissue Bank in South Africa experienced an ever increase in costs to enhance quality/safety controls: increase in historical patient information, documentation and serological testing in a population struggling to control HIV. To date, the South African Tissue Bank has not experienced any untoward patient incidence since the 1960s and currently is getting over 500 donors per year.     

Ascorbic acid feeding of rats reduces copper absorption,causing impaired copper status and depressed biliary copper excretion

The feeding of diets enriched with ascorbic acid (10 g/kg) to rats has previously been shown to lower plasma and liver copper concentrations. The present studies corroborate this. We hypothesized that ascorbic acid initially reduces copper absorption, this effect being masked later by the stimulatory effect on copper absorption of the impaired copper status. We also hypothesized that the impaired copper status as induced by ascorbic acid feeding is followed by a diminished biliary excretion of copper in an attempt to preserve copper homeostasis. Our hypotheses are supported by the present studies. Ascorbic acid feeding initially reduced apparent copper absorption, and in the course of the experiment this effect tended to turn over into a stimulatory effect. Copper deficiency, as induced by feeding a diet containing 1 mg Cu/kg instead of 5 mg Cu/kg, systematically increased copper absorption. Biliary excretion of copper in rats given ascorbic acid was unaffected initialy but became depressed after prolonged ascorbic acid feeding. A similar time course was seen for fecal endogenous copper excretion that was calculated as the difference between true and apparent copper absorption. Copper deficiency systematically reduced biliary copper excretion and fecal endogenous copper loss.     

Het gesprek met de patiënt is essentieel voor goede farmacotherapeutische zorg

Frail elderly with polypharmacy are at greater risk of preventable medication-related health damage. To improve medication safety, the healthcare field prepared, in consultation with the Dutch Health Care Inspectorate, a number of guidelines and standards containing conditions for safe prescribing. According to these standards the active involvement of patients by health care professionals is essential for good pharmacotherapeutic care. However, two studies with patients show that there is still room for improvement. According to patients, they can be (even) better informed about changes in their medication. Also the caregivers could communicate more clearly who is the central contact point and who is ultimately responsible for the medication. Patients are not sufficiently informed on this. Furthermore, there is uncertainty about how and why medication reviews are performed. More explanation to patients about this is desirable. In addition, patients experience that keeping their medication list up to date and transferring medication data between health care providers could be improved. Finally, a group of patients welcomes the opportunity to co-decide on changes in their medication. In order to prescribe safely, it is crucial that caregivers actively involve patients in pharmacotherapeutic care and really enter into conversation with them about their medication.     

Nutrition and kidney calcification in rats

Nephrocalcinosis is a 'spontaneous' disorder in rats which refers to the deposition of calcium salts in the kidney, preferably in the cortico-medullary region. Studies using defined, semi-purified diets have shown that low dietary concentrations of magnesium, high concentrations of calcium, high concentrations of phosphorus and low calcium: phosphorus ratios induce kidney calcification. Dietary phosphorus induced nephrocalcinosis in female rats is associated with increased kidney size and weight, tubular hyperplasia, fibrosis and increased excretion of albumin in urine. This suggests that nephrocalcinosis may impair kidney function. In rats fed different commercial diets the incidence of nephrocalcinosis can vary considerably. Differences in the degree of nephrocalcinosis in different experiments may negatively influence the comparability of experimental outcome, especially when this is affected by kidney function and structure. Experimental data are needed so that diets can be formulated that do not produce nephrocalcinosis without inducing other disorders.     

Cholesterol metabolism and esterases in four strains of rats with differential cholesterolemic responses to a high-cholesterol, high-cholate diet

The increase in serum cholesterol after feeding a diet containing 2% (w/w) of cholesterol and 0.5% of cholate for 13 days was 200 and 800% in two hypo- and two hyper-responsive inbred strains of rats, respectively. While remaining on the high-cholesterol, high-cholate diet for longer periods, the level of serum cholesterol dropped in the hyper-responsive strains, and after 8 weeks on the diet one hyper-responsive strain had similar serum cholesterol concentrations as the two hypo-responsive strains. The feeding of a semipurified diet, containing 1% (w/w) of cholesterol and 20% of fat, did not discriminate between the two hypo- and hyper-responsive strains with respect to the response of serum cholesterol. The activities in plasma of the indicators for liver function, aspartate amino transferase and alkaline phosphatase, were significantly increased in all strains after feeding the high-cholesterol, high-cholate diet. Only alkaline phosphatase was increased by the semipurified diet. Evidence is presented that in the four inbred strains of rats the differential cholesterolemic response to the high-cholesterol, high-cholate diet is not related to the baseline serum lipoprotein profile, liver cholesterol accumulation, fecal bile acid excretion, and the total activities and patterns of esterases in serum, liver and small intestine.     

In Vitro and In Vivo Neuronal Electrotaxis: A Potential Mechanism for Restoration?

Electrical brain stimulation used to treat a variety of neurological and psychiatric diseases is entering a new period. The technique is well established and the potential complications are well known and generally manageable. Recent studies demonstrated that electrical fields (EFs) can enhance neuroplasticity-related processes. EFs applied in the physiological range induce migration of different neural cell types from different species in vitro. There are some evidences that also the speed and directedness of cell migration are enhanced by EFs. However, it is still unclear how electrical signals from the extracellular space are translated into intracellular actions resulting in the so-called electrotaxis phenomenon. Here, we aim to provide a comprehensive review of the data on responses of cells to electrical stimulation and the relation to functional recovery.