Guidance of thalamocortical axons by growth-promoting molecules in developing rat cerebral cortex

Substrate-bound guidance cues play an important role during the development of thalamocortical projections. We used time-lapse video microscopy to study the growth behaviour of thalamic axons on different substrates. On embryonic cortical membranes and on a pure laminin substrate, thalamic fibres advanced relatively slowly (approximately 15 microns/h) and on average their growth cones retracted transiently every approximately 5 h. In contrast, on membranes prepared from early postnatal cortex, thalamic fibres grew twice as fast and spontaneous growth cone collapse occurred approximately 8 times less often. Experiments in which we used the sugar-binding lectin peanut agglutinin or heat inactivation to change the membrane properties indicated that these differences are due to growth-supporting molecules on postnatal cortical membranes. When offered a choice between embryonic and postnatal cortical membranes, thalamic axons preferred the postnatal membrane substrate. Time-lapse imaging revealed that borders between these two substrates effectively guided thalamic fibres, and in most cases axons changed their direction without collapse of the growth cone. Our results suggest that thalamic axons can be guided by the spatial distribution of growth-promoting molecules in the developing cortex.

Increased degranulation of eosinophil and neutrophil granulocytes in cystic fibrosis

Increased serum and sputum concentrations of eosinophil cationic protein (ECP) and of neutrophil myeloperoxidase (MPO) have been described in patients with cystic fibrosis. Because numbers of eosinophils are normal in both peripheral blood and in the lung of patients with cystic fibrosis, we investigated whether eosinophils presented with an increased propensity to release their granule proteins. We investigated 20 patients with cystic fibrosis, 19 individuals with bronchial asthma, and 21 healthy nonatopic subjects. Isolated granulocytes were stimulated with serum-opsonized Sephadex G15 particles and the released amounts of ECP and MPO were measured by using radioimmunoassays. Eosinophils of patients with cystic fibrosis released significantly higher amounts of ECP than control subjects (p < 0.0001) and individuals with bronchial asthma (p < 0.0001). The release of MPO from neutrophils was also higher (p < 0.0001 and p < 0.005, respectively). Furthermore, a significant relationship between clinical variables and secretory activity of eosinophils was found in cystic fibrosis. We conclude that eosinophils as well as neutrophils obtained from patients with cystic fibrosis have an increased propensity to release their granule proteins which may be due to priming mechanisms. These findings would support anti-inflammatory treatment modalities in cystic fibrosis.

[Travel in the tropics and furunculoid myiasis. Botfly larva in a child]

Dipterous fly maggots of different species live worldwide as parasites in hooved mammals. In the host the larval development causes typical boils, i.e., abscesses including the larvae. As a result of increasing tourist traffic, travelers can also bring back to Germany tropical types of myiasis.

The specification of neuronal fate: a common precursor for neurotransmitter subtypes in the rat cerebral cortex in vitro

Neurotransmitter choice is a crucial step in neural development. In the cerebral cortex, pyramidal neurons use the excitatory neurotransmitter glutamate, whereas non-pyramidal cells use the inhibitory neurotransmitter GABA. We are interested in how these two neuronal types are generated. We labelled precursor cells from embryonic rat cerebral cortex with a retroviral vector in dissociated cell cultures, and examined the neurotransmitter phenotype of their progeny immunohistochemically after 2 weeks in vitro. We discovered, first, that precursor cells in culture generate glutamatergic and GABAergic neurons in proportions similar to those in vivo. Second, we found that neuronal precursor cells gave rise to both GABAergic and glutamatergic neurons. These results suggest that neuronal precursor cells in the cerebral cortex have the potential to generate both neuronal subtypes. Moreover, these data are consistent with a stochastic model of neurotransmitter specification.

Getting there and being there in the cerebral cortex

The mammalian neocortex is composed of functional areas that are specified to process particular aspects of information. How is this specification achieved during development? Since cells migrate to their final positions in the developing nervous system, a central issue is the relation between cellular migration and positional information. This review combines evidence for early positional specification in the developing cortex with evidence for cellular dispersion during migration. A model is suggested whereby stable cues provide positional information and minorities of 'displaced' cells are respecified accordingly. Comparison with other parts of the CNS reveals that cellular dispersal is ubiquitous and has to be included in any mechanism relaying positional specification. Ontogenetic and phylogenetic considerations suggest that radial glial cells might provide the positional information in the developing nervous system.

Anaphylaxis after dental treatment with a formaldehyde-containing tooth-filling material

A 67-year-old patient developed systemic reactions after application of a formaldehyde-containing tooth filling. She had a clearly positive RAST result for formaldehyde, whereas skin prick testing and patch tests were negative. Sensitization to formaldehyde appears to have occurred 1 year previously. Induction of formaldehyde allergy may represent a major complication during dental treatment, and assessment of specific IgE should be considered in patients at risk.

Comparison of ultrasonographic and radiographic findings in cows with traumatic reticuloperitonitis

The radiographic and ultrasonographic findings in 26 cows with traumatic reticuloperitonitis were compared. The cows were divided into three groups based on the radiographic findings; the first group consisted of 12 cows in which the principal radiographic finding was a foreign body penetrating the reticulum; the second group contained four cows in which the principal radiographic finding was gas shadows or a gas-fluid interface, the third group consisted of 10 cows that had no reliable radiographic evidence of traumatic reticuloperitonitis, such as an abnormal contour, position or shape of the reticulum. In no case could the foreign bodies be visualised by ultrasonography. In all the cows except one with radiographic evidence of abnormal gas inclusions and gas-fluid interfaces, ultrasonography revealed echogenic, partitioned and capsulated structures with central hypoechogenic cavities. In addition, in some of the cows with no radiographic evidence of the condition, severe changes indicative of inflammatory processes were visible by ultrasonography.

Cortical and striatal neurone number in Huntington's disease

The total cortical and striatal neurone and glial numbers were estimated in five cases of Huntington's disease (three males, two females) and five age- and sex-matched control cases. Serial 500-microns-thick gallocyanin-stained frontal sections through the left hemisphere were analysed using Cavalieri's principle for volume and the optical disector for cell density estimations. The average cortical neurone number of five controls (mean age 53 +/- 13 years, range 36-72 years) was 5.97 x 10(9) +/- 320 x 10(6), the average number of small striatal neurones was 82 x 10(6) +/- 15.8 x 10(6). The left striatum (caudatum, putamen, and accumbens) contained a mean of 273 x 10(6) +/- 53 x 10(6) glial cells (oligodendrocytes, astrocytes and unclassifiable glial profiles). The mean cortical neurone number in Huntington's disease patients (mean age 49 +/- 14 years, range 36-75 years) was diminished by about 33% to 3.99 x 10(9) +/- 218 x 10(6) nerve cells (P < or = 0.012, Mann-Whitney U-test). The mean number of small striatal neurones decreased tremendously to 9.72 x 10(6) +/- 3.64 x 10(6) (-88%). The decrease in total glial cells was less pronounced (193 x 10(6) +/- 26 x 10(6)) but the mean glial index, the numerical ratio of glial cells per neurone, increased from 3.35 to 22.59 in Huntington's disease. Qualitatively, neuronal loss was most pronounced in supragranular layers of primary sensory areas (Brodmann's areae 3,1,2; area 17, area 41). Layer IIIc pyramidal cells were preferentially lost in association areas of the temporal, frontal, and parietal lobes, whereas spared layer IV granule cells formed a conspicuous band between layer III and V in these fields. Methodological issues are discussed in context with previous investigations and similarities and differences of laminar and lobar nerve cell loss in Huntington's disease are compared with nerve cell degeneration in other neuropsychiatric diseases.

Quantitative investigations on the human entorhinal area: left-right asymmetry and age-related changes

The total nerve cell numbers in the right and in the left human entorhinal areas have been calculated by volume estimations with the Cavalieri principle and by cell density determinations with the optical disector. Thick gallocyanin-stained serial frozen sections through the parahippocampal gyrus of 22 human subjects (10 female, 12 male) ranging from 18 to 86 years were analysed. The laminar composition of gallocyanin (Nissl)-stained sections could easily be compared with Braak's (1972, 1980) pigmentoarchitectonic study, and Braak's nomenclature of the entorhinal laminas was adopted. Cell-sparse laminae dissecantes can more clearly be distinguished in Nissl than in aldehydefuchsin preparations. These cell-poor dissecantes, lamina dissecans externa (dis-ext), lamina dissecans 1 (dis-1) and lamina dissecans 2 (dis-2), were excluded from nerve cell number determinations. An exact delineation of the entorhinal area is indispensable for any kind of quantitative investigation. We have defined the entorhinal area by the presence of pre-alpha cell clusters and the deeper layers of lamina principalis externa (pre-beta and gamma) separated from lamina principalis interna (pri) by lamina dissecans 1 (dis-1). The human entorhinal area is quantitatively characterized by a left-sided (asymmetric) higher pre-alpha cell number and an age-related nerve cell loss in pre as well as pri layers. At variance with other CNS cortical and subcortical structures, the neuronal number of the entorhinal area appears to decrease continuously from the earliest stages analysed, although a secular trend has to be considered. The asymmetry in pre-alpha cell number is discussed in the context of higher human mental capabilities, especially language.

Cystic fibrosis screening in neonates--measurement of immunoreactive trypsin and direct genotype analysis for delta F508 mutation

This study investigated the clinical usefulness of screening for cystic fibrosis (CF) in 19,992 newborns, over 39 months, in an Austrian population. Immunoreactive serum trypsin (IRT) determination was followed by sweat chloride analysis (sweat test) to establish diagnosis. In a retrospective analysis covering 6 months of the study period, individuals who were considered to be at risk after IRT estimation (n = 22) were analysed for delta F508 mutation, using a new method of DNA extraction from the initial dried blood specimens. A total of 119 infants (0.6%) had values greater than 750 ng trypsin/ml whole blood. In 88 babies sweat tests were performed, leading to the diagnosis of CF in 11 cases. One patient was not initially identified by screening but was later discovered due to his clinical status. Three infants were noted to carry the delta F508 mutation (1 homozygous, 2 heterozygous). Two of these babies already had CF. The second heterozygote was a carrier. A highly efficient three tier screening strategy is presented in which IRT estimation, determination of delta F508 status and sweat chloride testing could lead to a high sensitivity analysis of this population.

Utilization of prenatal diagnosis for cystic fibrosis over the past seven years

OBJECTIVE

First trimester prenatal diagnosis (PD) by DNA analysis for cystic fibrosis (CF) has been available for parents of affected children since May 1986.

METHODS

In a prospective study 37 couples with a single child affected by CF were investigated. Fathers and mothers were interviewed simultaneously, and their attitudes towards further childbearing and potential utilization of PD ascertained. Parental answers were treated as one. A 7-year follow-up allowed comparison between intended and actual behavior.

RESULTS

At the time of the interview, 16 parents (43%) were determined to have further children. Nineteen parents (51%) said they would certainly or probably utilize PD in case of pregnancy. Their predominant reason for favoring PD was the strong desire to have a healthy child (47%). Among the 18 rejectors (49%) the fear of an unsolvable conflict in case of an affected fetus prevailed (39%). Twenty-four pregnancies actually occurred in 18 families. Utilization of PD was arranged in five (21%) and finally performed in four (17%) cases.

CONCLUSION

Availability of PD does not substantially change the reproductive behavior of parents of children with CF. Reasons for this were multifactorial, with anticipated difficulty in deciding to continue or terminate pregnancy being predominant.

Forearm BMD as measured by peripheral quantitative computed tomography (pQCT) in a German reference population

Low bone mass as estimated by decreased bone mineral density (BMD) is an established predictor of osteoporotic fractures. One of the latest developments in bone densitometry is peripheral quantitative computed tomography (pQCT) of the forearm. In Germany, the CT bone scanner XCT 900 has already been widely used; however, interpretation of measurements with respect to osteoporosis risk assessment can be improved by better defined and validated reference data. In the present study, this device was used to measure BMD at the distal radius in a well-defined healthy population of 179 German adults (91 men, 88 women) aged 20-79 years. In vivo precision was 1.67% for trabecular and 0.81% for total BMD measurements. Peak values of trabecular and total BMD were observed at the ages 40-50 years in women and 30-40 years in men. Beyond these ages, both trabecular and total BMD showed a linear decline with age, decreasing by 0.85% and 1.08% per year in women and by 0.59% and 0.54% in men, respectively. Measures of BMD were not influenced by weight, height or body mass index (BMI). In both sexes, trabecular and total radial BMD showed a positive and significant correlation with femoral BMD measures obtained by dual X-ray absorptiometry (DXA). Weaker correlations were observed with DXA measures of the lumbar spine. Compared with the 95% reference range provided by the manufacturer, the distribution of age- and sex-specific values of trabecular BMD of the distal radius was shifted to lower values by up to 1 standard deviation.(ABSTRACT TRUNCATED AT 250 WORDS)

Eosinophilic activation in cystic fibrosis

BACKGROUND

The neutrophil is a potent contributor to pulmonary destruction in cystic fibrosis. Since eosinophils also possess destructive potential the involvement of eosinophils in cystic fibrosis has been investigated.

METHODS

Eosinophil numbers and levels of eosinophil cationic protein (ECP), a marker of eosinophil activation, were determined in the serum of 42 patients with cystic fibrosis and in the sputum of 10 of them. To determine neutrophil activation levels of myeloperoxidase (MPO) were also measured.

RESULTS

In cystic fibrosis increased serum levels of ECP were detected compared with healthy non-atopic subjects. Serum ECP levels were not related to the peripheral blood eosinophil count. A strong correlation with ECP concentrations in sputum indicated that the level of ECP in serum was representative of its pulmonary level. Levels of MPO were also increased in cystic fibrosis. A strong correlation was found between MPO and pulmonary function. In addition, ECP was related to arterial oxygen and carbon dioxide tensions. Antibiotic treatment reduced neutrophil activation without effect on ECP levels.

CONCLUSIONS

Until now Pseudomonas aeruginosa and neutrophils were held to be primarily responsible for progressive tissue damage in cystic fibrosis. The results of this study suggest that eosinophils might also participate in such pulmonary destruction.

Eosinophilic activation in cystic fibrosis

BACKGROUND

The neutrophil is a potent contributor to pulmonary destruction in cystic fibrosis. Since eosinophils also possess destructive potential the involvement of eosinophils in cystic fibrosis has been investigated.

METHODS

Eosinophil numbers and levels of eosinophil cationic protein (ECP), a marker of eosinophil activation, were determined in the serum of 42 patients with cystic fibrosis and in the sputum of 10 of them. To determine neutrophil activation levels of myeloperoxidase (MPO) were also measured.

RESULTS

In cystic fibrosis increased serum levels of ECP were detected compared with healthy non-atopic subjects. Serum ECP levels were not related to the peripheral blood eosinophil count. A strong correlation with ECP concentrations in sputum indicated that the level of ECP in serum was representative of its pulmonary level. Levels of MPO were also increased in cystic fibrosis. A strong correlation was found between MPO and pulmonary function. In addition, ECP was related to arterial oxygen and carbon dioxide tensions. Antibiotic treatment reduced neutrophil activation without effect on ECP levels.

CONCLUSIONS

Until now Pseudomonas aeruginosa and neutrophils were held to be primarily responsible for progressive tissue damage in cystic fibrosis. The results of this study suggest that eosinophils might also participate in such pulmonary destruction.

Perspectives of longitudinal growth in cystic fibrosis from birth to adult age

The longitudinal growth in 139 patients with cystic fibrosis (CF) was investigated from birth until the age of 19 years. Already at birth weight and length were reduced (weight: -0.83 +/- 0.13 SDS in girls, -0.44 +/- 0.13 SDS in boys; length: 0.55 +/- 0.13 SDS in girls, -0.39 +/- 0.14 SDS in boys; mean +/- SEM). Both variables showed a further decline until diagnosis was established (weight: -1.57 +/- 0.21 SDS in girls, -1.46 +/- 0.25 SDS in boys; length: -1.15 +/- 0.32 SDS in girls, -1.03 +/- 0.52 SDS in boys; mean +/- SEM). Six to 12 months after diagnosis length improved and reached the 25th percentile in both sexes. Height and weight followed the 25th percentile throughout childhood. Growth velocity was fairly normal during this period. There was a loss in percentiles of both height and weight after the age of 8 years and the pubertal growth spurt was delayed and reduced. However, the 25th percentile was reached again in the adolescent period. At the age of 19 years median height was 161.5 cm in girls and 173 cm in boys, both representing the 25th percentile. Using a sensitive statistical method for analysis of growth data we present CF specific growth curves for height, weight and growth velocity. There was no significant effect of pulmonary colonization with Pseudomonas aeruginosa on growth velocity.

Ultrasonography of the reticulum in cows

The reticulum and adjacent organs were examined ultrasonographically in 51 cows by use of a 3.5-MHz linear transducer applied to the ventral aspect of the thorax over the sixth and seventh intercostal spaces. Examination included assessment of the contour of the reticulum, of reticular contractions, and of the organs adjacent to the reticulum. The normal reticulum appeared as a half-moon-shaped structure with a smooth contour; it contracted at regular intervals and was situated immediately adjacent to the diaphragm and ventral portion of the abdominal wall when relaxed. Contents of the reticulum could not normally be imaged because of its partly gaseous composition. The ruminoreticular groove, craniodorsal blind sac of the rumen, and the ventral sac of the rumen were observed caudally. The distal aspect of the spleen and parts of the omasum, abomasum, and liver could be imaged. Reticular motility was characterized by a biphasic contraction pattern. Four biphasic reticular contractions usually were observed during a 4-minute period. During the first (incomplete) contraction, the reticulum contracted by a mean of 7.2 +/- 2.30 cm. There was then low-grade, incomplete relaxation of the reticulum, followed immediately by the second reticular contraction, during which the reticulum usually disappeared from the 17.5-cm-deep screen. The reticulum then reappeared in its normal position. The first reticular contraction lasted a mean of 2.6 +/- 0.33 seconds and the second contraction lasted 3.9 +/- 0.55 seconds. The mean interval between 2 biphasic contractions was 44.9 +/- 10.53 seconds. The speed of the first reticular contraction was 5.4 +/- 1.32 cm/s.(ABSTRACT TRUNCATED AT 250 WORDS)

Differentiation of transmitter phenotypes in rat cerebral cortex

Cortical neurons differ in their neurochemical properties. Projection neurons use excitatory amino acids as transmitters, most local interneurons contain the inhibitory transmitter GABA, and specific subtypes of local circuit neurons express distinct neuropeptides. How this cellular diversity is generated during development is not known. We have been studying the transmitter differentiation of cortical neurons in different in vitro systems using immunohistochemical techniques. Transmitter phenotypes of cortical neurons were examined in slice cultures, i.e. in the absence of extrinsic cortical connections, and in dissociated cortical cell cultures, i.e. in the absence of extrinsic and intrinsic cortical connections. The expression of vasoactive intestinal polypeptide in cortical interneurons occurred normally in slice cultures prepared from neonatal rats between birth and 2 days of age, but was strongly impaired in dissociated cell cultures prepared at the same time. These results suggest that the intact cortical environment present in the slice cultures exerts crucial influences for neuropeptide differentiation. In contrast, the transmitters glutamate and GABA were expressed normally in the appropriate cell types and similar in proportions in dissociated cell cultures prepared from cortices at embryonic day 19. Only cells dissociated during S-phase failed to express glutamate and GABA in vitro. When cells were kept for 24 h after mitosis in a cortical slice preparation in vitro, however, they later expressed their appropriate transmitter phenotypes. Thus, signals from the local cortical environment that act early in the cell cycle are required for the specification of transmitter phenotypes of cortical neurons.

The red wine provocation test: intolerance to histamine as a model for food intolerance

Sneezing, flush, headache, diarrhea, skin itch, and shortness of breath are symptoms occurring in patients intolerant to wine after drinking one glass of red wine. The role of histamine in wine intolerance was evaluated by a red wine provocation test in 28 patients with a history of wine intolerance and in 10 controls with good tolerance of wine. Patients were challenged with 125 ml red wine (equivalent to 50 micrograms histamine); blood samples were drawn before and after 15 and 30 minutes. Plasma histamine was assessed by a radioimmunoassay. Lung function tests were performed before and after the wine test. Twenty-two of twenty-eight patients had symptoms showing significantly higher plasma histamine levels 30 minutes after wine challenge (p < .01) compared with asymptomatic controls. Basal histamine levels of patients were higher (p < .05) than in controls. A slight asthmatic attack as well as a 30% decrease of FEF 25 was seen in 2/22 patients. Terfenadine premedication significantly eliminated symptoms in 10/12 patients (p < .05) in a subsequent wine test. Histamine assessment was done in 52 wines (red, white, and champagne) and in 17 beers by radioimmunoassay. Histamine levels ranged from 3-120 micrograms/l in white wines; 15-670 micrograms/l in champagnes; 60-3800 micrograms/l in red wines; and 21-305 micrograms/l in beers. Histamine is causing wine intolerance. Patients intolerant to wine seem to have diminished histamine degradation probably based on a deficiency of diamine oxidase.

Histamine-free diet: treatment of choice for histamine-induced food intolerance and supporting treatment for chronic headaches

Histamine-induced food intolerance is not IgE-mediated. Skin-prick testing and specific IgE to food allergens are typically negative. Food rich in histamine or red wine may cause allergy-like symptoms such as sneezing, flush, skin itching, diarrhoea and even shortness of breath. The suspected reason is a diminished histamine degradation based on a deficiency of diamine oxidase. As diamine oxidase cannot be supplemented, a histamine-free diet was implemented to reduce histamine intake. Forty-five patients with a history of suffering from intolerance to food or wine (n = 17) and chronic headache (n = 28) were put on the diet over months to years. Fish, cheese, hard cured sausages, pickled cabbage and alcoholic beverages had to be avoided. Complaint intensity and drug-use per week prior to and 4 weeks after a histamine-free diet were compared. After 4 weeks on the diet 33/45 patients improved considerably (P < 0.01), eight of them had total remission. In 12/45 patients, however, no changes in symptoms were observed. Symptoms of food or wine intolerance significantly decreased (P < 0.02; treatment of choice), headaches decreased in frequency (P < 0.001), duration and intensity. After eating histamine-rich food symptoms were reproducible and could be eliminated by anti-histamines in most patients. These data indicate the role of histamine in food and wine intolerance and that histamine-rich food causes a worsening of symptoms in patients suffering from chronic headaches. Results obtained support the hypothesis of a deficiency of diamine oxidase in patients with intolerance to food or wine.

Spontaneous histamine release in whole blood in patients before and after 4 months of specific immunotherapy

Spontaneous histamine release (SHR) in whole blood was assessed before and after 4 months of specific immunotherapy (SIT) for allergic rhinoconjunctivitis in 32 patients. Spontaneous histamine release was significantly enhanced (P < 0.05) in patients prior to immunotherapy compared with 20 controls. Spontaneous histamine release decreased significantly in patients after 4 months of specific immunotherapy (P < 0.04) and almost reached the same values as spontaneous histamine release in controls. Clinical success of treatment after 4 months was seen in 15 patients (improvement > or =50%), 10 of whom showed a significant decrease in spontaneous histamine release. Decrease of spontaneous histamine release after 4 months indicates the efficacy of specific immunotherapy already at an early stage of treatment. Assessment of spontaneous histamine release appears to be a useful and easily performable method for monitoring success of treatment of patients during specific immunotherapy.

Ultrasonographic findings in cows with traumatic reticuloperitonitis

The morphological changes in the region of the reticulum were examined ultrasonographically in 26 cows with traumatic reticuloperitonitis, and a radiograph of the reticulum was also taken. The ultrasonographic examination included observations of reticular motility during a three minute period, of reticular contours and of adjacent structures such as the diaphragm, the anterior dorsal blind sac of the rumen, the ventral sac of the rumen, the spleen, omasum, abomasum and liver. In cows with disturbed reticular motility, biphasic contractions were slower than normal or indistinct, and the number of contractions was reduced. Fibrinous changes appeared as echogenic deposits, sometimes accompanied by hypoechogenic fluid. Abscesses had an echogenic capsule with a hypoechogenic centre. In seven cows, there was an effusion in the region of the reticulum in addition to the morphological changes. The spleen was involved in the adhesions in four cows, the omasum in three cows, the liver in one cow and the abomasum in one cow. Radiography revealed foreign bodies penetrating the reticulum of 12 cows and magnets in the reticulum of seven cows. None of these foreign bodies or magnets could be visualised by ultrasonography.

Ethylmercuric chloride: the responsible agent in thimerosal hypersensitivity

The causative agent of thimerosal allergy (sodium ethylmercury thiosalicylate) has not previously been thoroughly investigated. To evaluate whether the organic mercury component or the thiosalicylic acid molecule induces thimerosal sensitization, 23 patients positive to thimerosal were patch tested with ethylmercuric chloride, thiosalicylic acid and 8 different derivatives of mercury. To date, ethylmercuric chloride has not been tested in thimerosal allergy. 19/23 patients (82%) showed positive patch test reactions to ethylmercuric chloride. 4/23 patients negative to ethylmercuric chloride reacted positively to thimerosal 0.1% but not to thimerosal 0.05%. 8/23 patients (35%) also reacted to other mercurials. 20 controls negative to thimerosal showed negative patch test reactions to ethylmercuric chloride. Neither patients nor controls reacted to thiosalicylic acid. These results indicate that testing with thimerosal 0.1% leads to false-positive reactions and that the ethyl mercury component is the responsible agent in thimerosal allergy.

[The histamine-free diet]

Food intolerance is not IgE-mediated but caused by histamine. A diminished histamine degradation based on a deficiency of diaminoxidase is suspected to be the reason. The therapeutic efficacy of a histamine-free diet was evaluated in 100 patients with food intolerance and allergic diseases, who were required to avoid fish, cheese, hardcured sausage, pickled cabbage, wine and beer for 4 weeks. Considerable improvement was observed in 57 patients, 15 of whom had total remission. The most striking treatment results were obtained in food or wine intolerance (80% P < 0.05; treatment of choice), bronchial asthma (80%), headache (64%) and urticaria (58%). After ingestion of food rich in histamine clearcut recurrence of atopic eczema was seen in 50% of the patients affected. Histamine plays a major part in food and wine intolerance. Histamine in food causes worsening of symptoms in atopics and patients suffering from headache. The results obtained indicate a deficiency of diaminoxidase in patients with intolerance to food or wine. Histamine levels in alcoholic beverages should be displayed on the labels.

Reconstructing cortical connections in a dish

During development of the cortex, efferent projection neurons located in distinct cortical layers send their axons to different targets, and afferent fibers establish connections with cortical target cells of a particular layer. Recent studies have shown that layer- and cell-specific afferent and efferent cortical connections established in culture are similar to those observed in vivo. The results of these experiments provide evidence for the existence of diffusible and membrane-bound guidance factors for specific sets of axons. Furthermore, they suggest the use of different molecules to navigate axons towards their target, regulate target innervation and mediate target cell recognition.

Nimodipine inhibits [3H]nitrobenzylthioinosine binding to the adenosine transporter in human brain

The inhibition of [3H]nitrobenzylthioinosine ([3H]NBI) binding to human parietal cortex membranes by adenosine transport inhibitors, adenosine receptor agonists and antagonists and dihydropyridines was investigated. While the adenosine transport inhibitors inhibited [3H]NBI binding with Ki values in the low nanomolar range and the adenosine A1 receptor agonist, cyclopentyladenosine, with a Ki in the low micromolar range, no IC50 values could be obtained for the adenosine receptor antagonists at concentrations up to 100,000 nM. Among the dihydropyridines (+)-nimodipine was the most potent with a Ki of 201 +/- 55 nM. Inhibition of adenosine transport thus may contribute to the clinical effects of nimodipine in the central nervous system.

[High-resolution computed tomography of the lung in young patients with cystic fibrosis]

In a prospective study we proved the value of high-resolution computed tomography (HRCT) and the CT scoring system developed by Stiglbauer et al. on 47 young patients suffering from cystic fibrosis (CF) (median age: 10.1 years). The most frequent pulmonary finding was bronchial wall thickening (BWT) in 43 patients (94.6%), followed by bronchiectasis (BE) in 36 patients (79.2%). A less frequent finding was ill-defined patchy consolidation (39.6%). We found an almost even distribution of BWT and BE in the upper and lower lobes of the lung. These two findings were scored according to their severity and extent. The maximum possible score for BWT and BE was 72 in a single patient. For both the overall score was 19.9 +/- 11.1. A statistically significant correlation of the CT scoring system with the lung function tests FEV1/FVC (P = 0.03) and MEF50 (P = 0.02) was found. The results of HRCT and the CT scoring system were shown to be valuable methods in the assessment of pulmonary changes, in young patients suffering from CF.

Immuno-allergologic aspects of childhood asthma

Asthma has a major impact on the health of children. Airway inflammation and bronchial hyperresponsiveness of variable severity have presently come to be considered underlying the pathogenesis and pathophysiology of the condition. Atopy in infancy seems to predict the severity of bronchial hyperresponsiveness in later childhood. Genetic predisposition, allergen exposure and contributory factors combine to set the clinical picture. Early sensitization to ingested or inhaled allergens accelerates development of allergic asthma. In children, the activity of inflammation can be assessed by estimation of indirect markers.

High resolution CT in children with cystic fibrosis

High resolution CT (HRCT) was performed in 24 children (median age 57.9 months) suffering from cystic fibrosis (CF). In 23 patients (one examination unacceptable because of motion artifacts) the most frequent finding was bronchial wall thickening, shown in 21 patients (91%), followed by bronchiectasis in 15 patients (65%). Less frequent findings were mucus plugging and patchy consolidations, which could be demonstrated in 11 patients each (48%). Findings were classified using a CT scoring system and including only irreversible pulmonary changes; a statistically significant correlation with lung function tests (FEV1/FVC; MEF50) could be established. HRCT to date seems to be the most valuable method to determine extent and severity of lung involvement in children with CF and should therefore be routinely used for the staging of this disease.

Assessment of histamine release from basophils in whole blood by benzylpenicilloyl poly-L-lysine in penicillin-sensitized patients

Histamine release from basophil granulocytes in whole blood by benzylpenicilloyl poly-L-lysine (PPL) was investigated in 7 patients with penicillin allergy. All patients presented with systemic immediate hypersensitivity reactions after i.v. administration of penicillin G. Total histamine (of 7 patients) ranged from 27.5 ng/ml to 62.1 ng/ml (mean 43.2 ng/ml). The spontaneous histamine release ranged from 0.15% to 5.1% (mean 1.8%) of the total content. Addition of PPL in various concentrations resulted in values between 0.8 and 9.6%. Although PPL is a reliable allergen for prick- and intradermal testing in the diagnosis of penicillin allergy--demonstrating a histamine liberation in the skin--the in vitro experiment using the same allergen showed no histamine release above 10%. Using a threshold of 5% out of 7 patients, 4 (57%) would show a positive histamine release. Therefore it might indicate that in penicillin allergy a threshold of 5% must be used. In addition, basophils in whole blood and skin mast cells may be activated differently.

Distilled water challenges in asthmatic children. Comparison of different protocols

Inhalation of ultrasonically nebulized distilled water (UNDW) appears a promising candidate for routine challenge testing in bronchial asthma. We have compared two different methods of application of UNDW in 12 asthmatic children with a positive response to methacholine provocation (MCh), in an attempt to increase UNDW sensitivity and to establish standard testing protocols. In addition, results from UNDW challenges were compared to responses to inhalation of jet-nebulized distilled water (JNDW) and cold air (CACh). Compared to MCh, the sensitivity of continuously or intermittently (iUNDW) inhaled UNDW was 67 percent or 75 percent, respectively, when a positive response was defined by a greater than or equal to 20 percent fall in FEV1, but was higher when definition of a positive response was based on results from flow volume curves. Sensitivity of continuous or intermittent inhalation of JNDW was lower than for UNDW. The UNDW inhalations were better tolerated than CACh. Following stepwise iUNDW challenge, there was a clear reaction plateau for all variables measured. Results indicate that testing protocols with iUNDW inhalations over 6 to 10 min (corresponding to 7 to 11 ml water inhalation) yield the maximum sensitivity attainable with UNDW challenges, and require a minimum of patient and investigator effort.

Formation and preservation of cortical layers in slice cultures

During cortical development, neurons generated at the same time in the ventricular zone migrate out into the cortical plate and form a cortical layer (Berry and Eayrs, 1963, Nature 197:984-985; Berry and Rogers, 1965, J. Anat. 99:691-709). We have been studying both the formation and maintenance of cortical layers in slice cultures from rat cortex. The bromodeoxyuridine (BrdU) method was used to label cortical neurons on their birthday in vivo. When slice cultures were prepared from animals at different embryonic and postnatal ages, all cortical layers that have already been established in vivo remained preserved for several weeks in vitro. In slice cultures prepared during migration in the cortex, cells continued to migrate towards the pial side of the cortical slice, however, migration ceased after about 1 week in culture. Thus, cortical cells reached their final laminar position only in slice cultures from postnatal animals, whereas in embryonic slice, migrating cells became scattered throughout the cortex. Previous studies demonstrated that radial glia fibers are the major substrate for migrating neurons (Rakic, 1972, J. Comp. Neurol. 145:61-84; Hatten and Mason, 1990, Experientia 46:907-916). Using antibodies directed against the intermediate filament Vimentin, radial glial cells were detected in all slice cultures where cell migration did occur. Comparable to the glia development in vivo, radial glial fibers disappeared and astrocytes containing the glia fibrillary-associated protein (GFAP) differentiated in slice cultures from postnatal cortex, after the neurons have completed their migration. In contrast, radial glial cells were detected over the whole culture period, and very few astrocytes differentiated in embryonic slices, where cortical neurons failed to finish their migration. The results of this study indicate that the local environment is sufficient to sustain the layered organization of the cortex and support the migration of cortical neurons. In addition, our results reveal a close relationship between cell migration and the developmental status of glial cells.

Determinants of airway response to challenge with distilled water in a population sample of children aged 7 to 10 years old

We challenged 446 schoolchildren and measured the percent decrease in FEV1 following 10 min of tidal inhalation of UNDW. Assessment tools for respiratory symptoms and atopy were questionnaire and skin testing, respectively. A previous diagnosis of asthma was most strongly associated with a positive airway response (defined as a fall in FEV1 greater than or equal to 10 percent. A positive response was also associated with atopy, presence of cough, cough during night, or any respiratory symptom. A child's age and the prechallenge FEF75% also explained response to distilled water indicating less responsiveness for older children and those with relative greater airway diameter. For the previous diagnosis of asthma, a positive distilled water challenge test had a sensitivity of 36 percent and a specificity of 92 percent. We conclude that a significant relationship between airway response to distilled water, asthma and symptoms suggestive for asthma exists for a childhood population sample.

Cold urticaria as a model of mediator release: platelet factor 4, eosinophil cationic protein and histamine

Platelet factor 4 (PF4) has previously been linked to precipitation of cold urticaria (CU). The aim of the study was to assess the liberation of PF4, eosinophil cationic protein (ECP) and histamine after cold challenge in patients with CU. Ten controls and 8 patients with CU verified by clinical data and cold challenge test were investigated. Assessment of histamine, ECP and PF4 were done using radioimmunoassays. In patients histamine increased after 10 min on the challenged arm (NS), PF4 increase was statistically significant (p less than 0.05) both in patients and controls. ECP release showed no significant changes. Treatment with doxepin results in clinical improvement, but no changes in mediator release were seen. Thus, in contrast to previous reports an increase of PF4 was seen both in controls as well as in patients. An involvement of ECP was not ascertained. Our data suggest that neither basophils, nor eosinophils or platelets are directly involved in cold urticaria and that mast cell-dependent mediators may be of greater relevance.

[Adherence of pacemaker electrodes to the endomyocardium--a postmortem study]

The weight of extraction of a pacemaker electrode from the endomyocardium was evaluated in 29 hearts (31 pacemakers). The maximum weight of extraction was 2375 g, the mean being 760 g. The weight of extraction depends on the duration of the implantation of the pacemaker, and on the thickness of the right ventricle, but there is no relationship to the shape of the pacemaker electrode, nor to the site of insertion in the right ventricular endomyocardium. In half the cases, pieces of endomyocardium adhered to the extracted electrode, the largest piece being 5 cm x 0.5 cm x 0.5 cm. The epicardium was not injured in any of these cases. It was often noticed that scarred adhesions existed between the cable of the pacemaker and the endocardium and/or the intima of the blood vessels. During traction in vivo, strangulation of the right heart and the blood vessels may occur.

Influence of the histamine control on skin reactivity in skin testing

We investigated the effect of the histamine control (1 mg/ml) on the results of skin prick and intradermal testing with bee and wasp venom. Skin tests were done on the patients' forearms: on the right arm the histamine control and the bee venom dilutions, on the left arm the wasp venom dilutions only, at distances of 4-5 cm. In intradermal testing 11 (9%) of 122 patients showed a positive wheal and flare reaction to the bee venom solution positioned next to the histamine control. The subsequent solutions in higher concentrations did not produce any skin reactions. The results of intradermal testing with bee venom did not occur in intradermal testing with wasp venom or in skin prick testing with both allergens. Our results show clearly that in skin prick tests a distance of 4-5 cm is sufficient to avoid false positive skin reactions. However, using the same distance in intradermal testing showed that histamine affects the skin reactions produced by adjacent allergen solutions. Therefore false positive results may occur.