Usefulness of erythrocyte protoporphyrin as a primary screening test for lead exposure in children

Erythrocyte protoporphyrin and blood lead concentrations were measured in samples from 583 Saudi children attending the outpatient clinics. Erythrocyte protoporphyrin concentrations showed poor correlation with blood lead concentrations of 25 ug dl^?1 and below. Measurement of erythrocyte protoporphyrin as a primary test for lead exposure is not recommended.     

Uroscopy in the 21st century: high-field NMR spectroscopy

From the experiments described, it can be seen that there are different research approaches that can be taken and these are summarized in Table 1. Whereas much scientific research is principally hypothesis led, there remains, nevertheless, an important place for exploratory research. High resolution NMR can measure, directly and simultaneously, a wide range of endogenous metabolites in biological fluids and has the unique capability of providing structural information on the metabolites detected. It has proved to be a powerful research tool with which to study inherited metabolic diseases, renal disease, drug metabolism, and toxicity, and can be used to monitor the effects of drug therapy. For instance, by using a library of experimental toxins one can map the metabolic profile of site-specific nephron injury. With this approach in man one could eventually take an unknown disease such as Balkan nephropathy and predict the initial site of tubular injury, the mode of injury and therefore the kind of toxin capable of producing that injury. NMR spectroscopic techniques are still advancing rapidly, with ever increasing sensitivity and sophistication of NMR pulse sequences to enhance structural elucidation in complex mixtures. Given the advances in directly coupled HPLC-NMR and even HPLC-NMR-mass spectroscopy it is likely that these technologies in conjunction with pattern recognition will make major contribution to our understanding of renal processes and provide new diagnostic insights in the 21st century.      

Giant infectious intracavernous carotid artery aneurysm presenting as intractable epistaxis

Infectious intracavernous carotid artery aneurysms usually present with ophthalmoplegia and/or signs of cavernous sinus thrombosis. We report an unusual case in which a patient with AIDS presented with intractable epistaxis secondary to rupture of a giant infectious intra-cavernous carotid artery aneurysm. Culture of the aneurysm grew mycobacterium avium intracellulare (MAI). The patient was treated successfully by excision of the aneurysm and reconstruction of the internal carotid artery with a saphenous vein interposition graft.     

Role of noradrenergic hyperactivity in neonatal opiate abstinence

Despite the existence of a well-defined abstinence syndrome in offspring of opiate-dependent mothers, the mechanisms involved in neonatal abstinence remain unclear. The goal of the present study was to determine the contribution of noradrenergic neurons in the opiate abstinence syndrome in neonatal rats (10 days old). First, the ability of the α2-adrenergic agonist, clonidine to attenuate the symptoms of neonatal opiate abstinence precipitated by naloxone was determined. Secondly, the activity of noradrenergic neurons was determined by measuring postmortem levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) in the hypothalamus, hippocampus and cortex in opiate-abstinent pups. Neonatal opiate abstinence was characterized by an increased incidence of wall climbing, tremors and mouthing. Acute treatment with morphine and naloxone in chronic saline-treated pups also produced the tremor, albeit less severe than in pups treated chronically with morphine. Clonidine (0.2 mg/kg) attenuated the expression of tremor and mouthing in neonates, but increased wall climbing. Clonidine elicited wall climbing in opiate-naive neonates. Treatment with morphine followed by naltrexone increased MHPG levels in all of the brain areas examined, irrespective of the chronic treatment, but naltrexone treatment elicited a larger increase in MHPG levels in pups treated chronically with morphine. Acute morphine treatment increased MHPG levels only in the hypothalamus. The results of the present study provide behavioral and neurochemical data supporting the hypothesis that noradrenergic hyperactivity plays a role in neonatal opiate abstinence.     

Hepatic nuclear and cytoplasmic effects following intermittent feeding of rats with di(2-ethylhexyl) phthalate

The effects on rats of intermittent feeding with the peroxisome proliferator and hepatocarcinogen di(2-ethylhexyl) phthalate (DEHP) have been examined. Male Wistar rats were fed for alternate 7-day periods diets containing 20,000 ppm DEHP or the control diet. The rats were examined 3 days after the start or recommencement of administration of the DEHP-containing diet or after 7 days on the control diet. After the commencement or recommencement of feeding with DEHP the expected increases in liver weight and in the number of peroxisomes were found. The increase in liver: body-weight ratio in response to administration of DEHP-containing diets was greater in rats that had been previously exposed to the compound, but re-administration of DEHP had a less marked effect on the increase in peroxisome number. Morphometric analysis showed that administration of DEHP-containing diets resulted in an increase in cell number in the liver and that a fall in the cell number occurred after the rats had been returned to the control diet for 7 days. Analysis of nuclear size gave results consistent with an increase in tetraploid hepatocytes after treatment with DEHP which was reversed when the rats were returned to control diet.     

The relationship between nasal airway cross-sectional area and nasal resistance

Mouth breathing in response to an impaired nasal airway is thought to have clinical consequences. Physiologically, mouth breathing occurs whenever the body senses that nasal resistance is inappropriately high. In physical terms mouth breathing is a response that enlarges the upper airway and, by doing so, reduces airway resistance. In the past measurements of nasal resistance have been used as an index of airway impairment. Recently, we introduced a technique that estimates cross-sectional size of the airway, a variable that directly determines the magnitude of airway resistance. The purpose of the present study was to determine the precise effects of nasal airway size on nasal airway resistance so that the relationship between the two could be described in mathematic terms. There were two phases to the study--one involving a model and simulated breathing, and the other involving 100 subjects demonstrating normal and impaired nasal airways. The pressure-flow technique for estimation of nasal airway size and nasal airway resistance was used. The following equation was generated from the data: Resistance = 1.9 + (Formula: see text). The relationship between the two variables is nonlinear--that is, size of the airway has its greatest effect on resistance when the airway is less than 0.4 cm2 and a much lesser effect at larger airway sizes. The study also showed that nasal airway resistance generally does not fall very much below 1.9 cm H2O/L/S during breathing even when the airway is very large. This probably relates to the need to maintain an adequate level of airway resistance for alveolar gas exchange.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dietary mannan-oligosaccharides and their effect on chicken caecal microflora in relation to Salmonella Enteritidis colonization

This study first investigates the effects of mash diet, or mash supplemented with either 2.5% mannose-oligosaccharide (MOS) or palm kernel meal (PKM), on the microflora of the hen caecal contents. Second, it investigates the effect of caecal contents of hens (HCC) fed mash or mash supplemented with MOS or PKM on the major microflora groups of chicks, and their inhibitory effect on Salmonella enterica serovar Enteritidis (PT4) colonization. Finally, this study investigates the effect over time of diets supplemented with MOS or PKM on S. Enteritidis colonization and the microflora of chicks. In hens, supplemented diets increased Bifidobacterium spp., while decreasing members of Enterobacteriaceae and Enterococcus spp., compared with the mash diet. Chicks dosed with the HCC showed, on average, increased numbers of anaerobes, while the numbers of aerobes decreased including coliforms and S. Enteritidis compared with controls without HCC. In chicks fed the MOS-supplemented or PKM-supplemented diets, S. Enteritidis colonization decreased over time, compared with mash alone. Four-week-old PKM birds showed an increase in Bifidobacterium spp. and Lactobacillus spp., with a decrease in S. Enteritidis compared with week 2. Generally, the HCC and diets supplemented with MOS or PKM affected the birds intestinal microflora by increasing the Bifidobacterium spp. and Lactobacillus spp., while decreasing the Enterobacteriaceae groups. They also reduced susceptibility in young chickens to colonization by S. Enteritidis.