Repeated measurements of mite and pet allergen levels in house dust over a time period of 8 years

BACKGROUND: Studies of the association between indoor allergen exposure and the development of allergic diseases have often measured allergen exposure at one point in time. OBJECTIVE: We investigated the variability of house dust mite (Der p 1, Der f 1) and cat (Fel d 1) allergen in Dutch homes over a period of 8 years. METHODS: Data were obtained in the Dutch PIAMA birth cohort study. Dust from the child's mattress, the parents' mattress and the living room floor was collected at four points in time, when the child was 3 months, 4, 6 and 8 years old. Dust samples were analysed for Der p 1, Der f 1 and Fel d 1 by sandwich enzyme immuno assay. RESULTS: Mite allergen concentrations for the child's mattress, the parents' mattress and the living room floor were moderately correlated between time-points. Agreement was better for cat allergen. For Der p 1 and Der f 1 on the child's mattress, the within-home variance was close to or smaller than the between-home variance in most cases. For Fel d 1, the within-home variance was almost always smaller than the between-home variance. Results were similar for allergen levels expressed per gram of dust and allergen levels expressed per square metre of the sampled surface. Variance ratios were smaller when samples were taken at shorter time intervals than at longer time intervals. CONCLUSION: Over a period of 4 years, mite and cat allergens measured in house dust are sufficiently stable to use single measurements with confidence in epidemiological studies. The within-home variance was larger when samples were taken 8 years apart so that over such long periods, repetition of sampling is recommended.     

Über Kompression und Narkose

Zusammenfassung Die Arbeit stellt den Begriff der Mechanonarkose auf und setzt Chemonarkose und Mechanonarkose in Parallele zueinander. Sowohl chemische Narkotica wie physikalische Kompression machen reversible Lähmungen und irreversible Schädigungen der verschiedensten tierischen und pflanzlichen Lebenserscheinungen, wobei die Lebewesen oder die Organe eines Lebewesens sich nach ihrer Empfindlichkeit und Resistenz in die gleiche Reihenfolge für beide Agentien anordnen. Beide machen in unternarkotischer Dosis allerlei Reizerscheinungen, in übernarkotischer Dosis an Muskeln Kontraktur und Verkürzung, und sind in ihrer Wirkung bis ins Einzelne vergleichbar. Als gemeinsame Erklärungsmöglichkeit für beide Agentien wird die Viscositätserhöhung an Zellgrenzen und Zelloberflächen mit ihrer Erschwerung von Diffusion und Stoffaustausch (Oberflächenverdichtung, Permeabilitätsabnahme) und ihren weiteren Folgen für den Zellstoffwechsel betrachtet.     

Ethische Aspekte der ästhetischen Medizin

The article examines the question whether and – if – under which conditions physicians should perform purely esthetic interventions. Starting point of the considerations is the special character of the medical profession and the necessity of the anticipated confidence in the system of medicine. The medical measures for aesthetic improvement are systematized. Medical measures to increase the wanted, positively felt attention of others are not compellingly required according to the medical ethic. Nevertheless they do not offend the ethos if high quality standards are insured: The measures must be presumably helpful for the patient; a thorough informed consent and avoidance of damage must be insured. Esthetic measures, in particular operations which are totally cosmetic, should be limited strictly if performed with children and adolescents. Nevertheless convincing arguments support medical-esthetic measures with children and adolescents to avoid stigmatization.     

Ultrastructural evidence for the uptake of a neurotoxic snake venom phospholipase A2 into mammalian motor nerve terminals

A mutant form of ammodytoxin A, a neurotoxic phospholipase A₂ from the venom of the long nosed viper Vipera ammodytes ammodytes, was prepared by site-directed mutagenesis, conjugated to a nanogold particle and inoculated into the antero-lateral aspect of one hind limb of female mice. Eight hours later the mice were killed, the soleus muscles of both ipsi- and contra-lateral hind limbs were removed, exposed to a silver enhancing medium and then prepared for transmission electron microscopy. Silver-enhanced particles were subsequently found concentrated in the peri-synaptic area, particularly within the synaptic gutter and the deep synaptic folds, and in many cases had been taken up into the cytoplasm of the terminal boutons of the motor axon. The results suggest that the presynaptic neurotoxicity of snake venom phospholipases A₂ involves several components of the neuromuscular apparatus, including intracellular organelles of the motor nerve terminal.     

Proton magnetic resonance spectroscopy in childhood brainstem lesions

Background Diagnosis of brainstem lesions in children based on magnetic resonance imaging alone is a challenging problem. Magnetic resonance spectroscopy (MRS) is a noninvasive technique for spatial characterization of biochemical markers in tissues and gives information regarding cell membrane proliferation, neuronal damage, and energy metabolism. Methods We measured the concentrations of biochemical markers in five children with brainstem lesions and evaluated their potential diagnostic significance. Images and spectra were acquired on a 1.5-T imager. The concentrations of N-acetylaspartate, tetramethylamines (e.g., choline), creatine, phosphocreatine, lactate, and lipids were measured within lesions located at the brainstem using Point-resolved spectroscopy sequences. Results Diagnosis based on localized proton spectroscopy included brainstem glioma, brainstem encephalitis, demyelination, dysmyelination secondary to neurofibromatosis type 1 (NF 1), and possible infection or radiation necrosis. In all but one patient, diagnosis was confirmed by biopsy or by clinical follow-up. Conclusions This small sample of patients suggests that MRS is important in the differential diagnosis between proliferative and nonproliferative lesions in patients without neurofibromatosis. Unfortunately, in cases of NF 1, MRS can have a rather misdiagnosis role.     

Chloroquine and hydroxychloroquine: side effect profile of important therapeutic drugs

Precise knowledge of the undesirable effects of chloroquine and hydroxychloroquine allows better exploitation of their therapeutic effects. Retinopathy can be avoided by observing a maximum daily dosage of 3.5-4 mg/kg ideal body weight for chloroquine and 6-6.5 mg/kg for hydroxychloroquine. In this way, both can be used for long-term therapy. The pharmacokinetics of chloroquine (storage in deep compartments with long plasma half-life) means that it can cumulate, especially with higher dosages and in the presence of renal or hepatic insufficiency. A high plasma concentration reinforces the side-effects without reinforcing the therapeutic effects. Besides subjective symptoms (e.g. anorexia, diarrhoea, nausea), the following undesirable reactions are significant. On the skin exanthema, hyperpigmentation and photodynamic reactions can develop. The hair can become white in blonde and red-haired men. In the eye, chloroquine deposits in the cornea and disturbances of accommodation can occur, besides retinopathy. Neuromyopathy and central nervous system disturbances (e.g. psychosis) are rare, as is impairment of auditory function or blood cells. During pregnancy there is a risk of potential fetal damage (hearing loss, abortion). An acute overdose is extremely dangerous: the lethal dose is 1 g for children and 4 g for adults. As death occurs rapidly, chloroquine has to be stored where it is absolutely inaccessible to children.