Differential morphology of the superior olivary complex of Meriones unguiculatus and Monodelphis domestica revealed by calcium-binding proteins.

In mammals, the superior olivary complex (SOC) of the brainstem is composed of nuclei that integrate afferent auditory originating from both ears. Here, the expression of different calcium-binding proteins in subnuclei of the SOC was studied in distantly related mammals, the Mongolian gerbil (Meriones unguiculatus) and the gray short-tailed opossum (Monodelphis domestica) to get a better understanding of the basal nuclear organization of the SOC. Combined immunofluorescence labeling of the calcium-binding proteins (CaBPs) parvalbumin, calbindin-D28k, and calretinin as well as pan-neuronal markers displayed characteristic distribution patterns highlighting details of neuronal architecture of SOC nuclei. Parvalbumin was found in almost all neurons of SOC nuclei in both species, while calbindin and calretinin were restricted to specific cell types and axonal terminal fields. In both species, calbindin displayed a ubiquitous and mostly selective distribution in neurons of the medial nucleus of trapezoid body (MNTB) including their terminal axonal fields in different SOC targets. In Meriones, calretinin and calbindin showed non-overlapping expression patterns in neuron somata and terminal fields throughout the SOC. In Monodelphis, co-expression of calbindin and calretinin was observed in the MNTB, and hence both CaBPs were also co-localized in terminal fields within the adjacent SOC nuclei. The distribution patterns of CaBPs in both species are discussed with respect to the intrinsic neuronal SOC circuits as part of the auditory brainstem system that underlie the binaural integrative processing of acoustic signals as the basis for localization and discrimination of auditory objects.

6-Aryl-4,5-dihydro-3(2H)-pyridazinones. A new class of compounds with platelet aggregation inhibiting and hypotensive activities.

This paper reports on the synthesis and pharmacological activity of 6-aryl-4,5-dihydro-3(2H)-pyridazinone derivatives. The compounds exhibit an aggregation inhibiting action on human platelets in vitro and on rat platelets under ex vivo conditions, as well as a hypotensive action on rats. The strongest pharmacological effects were found with dihydropyridazinones, which have a 6-[p-[(chloroalkanoyl)amino]phenyl] substituent, together with a methyl group in the 5-position. The antiaggregation activity of compounds of this type is in vitro up to 16000 times and ex vivo up to 370 times greater than that of acetylsalicylic acid; the hypotensive action is up to 40 times as great as that of the comparative substance dihydralazine.

Age-related pathophysiology of the blood-brain barrier in heat stress.

The possibility that the blood-brain barrier (BBB) might play an important role in the pathophysiology of heat stress (HS) has been examined in young (age 8-9 weeks) and adult (age 24-32 weeks) rats. Exposure of young rats to 4 h HS at 38 degrees C in a biological oxygen demand (BOD) incubator (relative humidity 47-50%, wind velocity 20-26 cm/sec, simulating the environmental conditions of Varanasi, India, during the month of June) resulted in a marked hyperthermia (41.7 +/- 0.23 degrees C) and behavioral symptoms. In these animals there was a profound increase in the permeability of the BBB to Evans blue-albumin (EBA) (464%) and to 131I-sodium iodide (515%), accompanied by a marked increase in the brain water content (4%), of the levels of serotonin (5-hydroxytryptamine, 5-HT) in plasma (687%) and in brain (267%) and a pronounced reduction (30%) in cerebral blood flow (CBF). Morphological examination using light- and electron-microscopy revealed profound neuronal changes associated with a marked increase in glial fibrillary acidic protein (GFAP) and in vimentin immunoreactivities, together with a substantial reduction in myelin basic protein (MBP) immunostaining in the brain. These changes were more pronounced in the brain-stem reticular formation, pons and medulla region. On the other hand, exposure of adult animals to the same intensity of HS resulted in mild or no changes in BBB permeability, content of brain water and 5-HT in the plasma and brain, CBF or other cellular changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Smoking and health: the role of the obstetrician and gynecologist.

PIP: In 1978 cigarette smoking was related to more than 320,000 deaths. A fifth of all cancer deaths are related to smoking. 30% of coronary artery disease, 75% of chronic bronchitis, 80% of emphysema, and 80% of lung cancer are associated with cigarette smoking. The habit costs society about $18 billion every year in lost work time and medical costs. The tobacco industry spends about $450 million annually to sell its product. Women now smoke the same amount as men. From 1969-75 the rate of smoking among girls aged 13-19 increased from 23% to 27%, about a half million new smokers. Over 70% of women under 35 surveyed indicated that their physicians had never mentioned nay of the dangers of smoking. Obstetricians and gynecologists are in an excellent position to counsel women against smoking since they often see teenagers right after they begin smoking. Since infant birth weight is lower when the mother smokes, further physiological effects are expected. The incidence of spontaneous abortion is doubled for the smoker. Between 1968-75, the proportion of physicians who smoked dropped from 29.6% to 21%. In the same 8-year period the percentage of pharmacists who smoked dropped from 34.5% to 27.5%. Nurses smoked 37.3% in 1968 and 38.9% in 1975. The time has come for the physician to take a stand against smoking.^ieng

Developmental changes of enzymes involved in peptide degradation in isolated rat brain microvessels.

The specific activities of aminopeptidase A (APA), aminopeptidase M (APM), and dipeptidyl-aminopeptidase IV (DP IV) were determined in isolated brain microvessels and in brain homogenate of rats with different ages (between 1 and 8 weeks old). In addition, the blood-brain barrier (BBB)-specific enzymes gamma-glutamyltranspeptidase (gamma-GT) and alkaline phosphatase (ALP) were measured. As similarly described by others, gamma-GT activity increased during this time period by fourfold, whereas ALP increased between weeks 1 and 2 and declined thereafter. DP IV activity increased fivefold during the first 8 weeks after birth and APM activity increased by twofold. A decrease of APA activity was found between weeks 1 and 2 after birth followed by an increase thereafter. The development of aminopeptidase activities responsible for the processing of specific neuropeptides acting on brain microvessels may be important in the development of regulation processes for cerebral blood flow and BBB permeability in the maturing animal.

Vasopressin binds to microvessels from rat hippocampus.

Recent evidence suggests that vasopressin may influence the permeability of the endothelium of brain capillaries. We measured the binding of [125I]arginine-8-vasopressin ([125I]AVP) to microvessels isolated from different regions of the rat brain. The study revealed saturable and specific binding of [125I]AVP to microvessels isolated from hippocampus. Scatchard analysis confirmed a single class of high affinity sites with an equilibrium dissociation constant, Kd, of 3.2 nM and an apparent maximal binding capacity of 205 fmol/mg protein. No binding was observed to microvessels from neocortex and striatum.

On the blood-brain barrier to peptides: specific binding of atrial natriuretic peptide in vivo and in vitro.

Using the intracarotid bolus injection technique, a saturable binding of [125I]atrial natriuretic peptide (ANP) was found in 8 blood-brain barrier (BBB)-protected rat brain regions as well as in the pineal gland, choroid plexus, neurointermediate and anterior lobes of the pituitary, i.e. structures lacking a BBB. The presence of specific ANP binding on the BBB, here shown for the first time by an in vivo approach, was evidenced concomitantly in vitro by incubation of isolated microvessels. A single-class high affinity binding without regional differences was obtained with Kd = 0.23 nM and Bmax = 120 fmol/mg protein. From that a density of 1,400 binding sites per endothelial cell was calculated, thought to be localized predominantly in the luminal membranes. In the in vivo study, the portion of the extracted peptide that, under the conditions used, may have crossed the BBB by passive diffusion amounted to less than 0.4% of the labeled ANP administered. ANP itself did not change the tightness of the BBB to the non-diffusible reference molecule [14C]inulin. In the BBB-free areas, ANP enhanced the inulin space by nearly 50%.

[A contribution to the radiology of cervical dysphagia (author's transl)]. / Beitrag zur Röntgenologie der zervikalen Dysphagie.

Typical appearances of the pharyngo-oesophageal transition zone are described. They are discussed in relation to the available methods of examination and related to the predominantly Anglo-Saxon literature of the last two decades.

[Atelectatic pseudo-tumours of the lung (round atelectases)]. / Uber atelektatische Pseudotumoren der Lunge

Following the publication of the paper by Hanke, a round atelectasis was diagnosed on six occasions in five of our patients (two radiologically and pathologically, four radiologically only). On the basis of this material, the radiological features of round atelectases are discussed. Hanke's findings are critically reviewed and a comparison with our material shows a number of differences. The term "atelectatic pseudotumour of the lung" is suggested.

[Round atelectasis]. / Die Rundatelektasen.

a) For several reasons Sinner's paper calls for critical remarks: His term "Pleuroma" for a neither pleural nor tumorous but intrapulmonary and atelectatic mass lesion lacks any anatomical and histological basis and is misleading at that because it pretends a tumor of the pleura; his statement in the summary that atelectatic pseudotumors of the lung show a tumorcell-like cytoarchitecture is surprising without being further discussed by the author; he encourages risky invasive diagnostical procedures even in cases where the radiological diagnosis of round atelectasis is unmistakable; already known radiologic features of round atelectases are presented by him as hitherto undescribed; his conceptions of the formal development of round atelectases and of their most characteristic features can not be agreed with. b) The different forms of round atelectases and their residuals are presented with tomograms and with diagrams of their formal development from our point of view.

[The radiology of the dorso-basal part of the chest (author's transl)]. / Beitrag zur Röntgenologie der dorsobasalen Thoraxergion

The radiology of the dorso-basal part of the chest includes a number of unmistakable lesions with characteristic appearances. These are demonstrated by a series of appropriate cases (diaphragmatic processes, pulmonary sequestrations, pleural disease and the late effects of a pneumothorax). Their differential diagnosis is discussed.

Competitive ligand exchange between Cu-humic acid complexes and methanobactin.

Copper has been found to play a key role in the physiology of methanotrophic micro-organisms, and methane oxidation may critically depend on the availability of Cu. In natural environments, such as soils, sediments, peat bogs, and surface waters, the presence of natural organic matter (NOM) can control the bioavailability of Cu by forming strong metal complexes. To promote Cu acquisition, methanotrophs exude methanobactin, a ligand known to have a high affinity for Cu. In this study, the capability of methanobactin for Cu acquisition from NOM was investigated using humic acid (HA) as a model substance. The kinetics of ligand exchange between Cu-HA and methanobactin was observed by UV-vis spectroscopy, and the speciation of Cu bound to methanobactin was determined by size-exclusion chromatography coupled to an ICP-MS. The results showed that Cu was mobilized from HA by a fast ligand exchange reaction following a second-order rate law with first-order kinetics for both methanobactin and Cu-HA complexes. The reaction rates decreased with decreasing temperature. Equilibrium experiments indicated that methanobactin was not sorbed to HA and proved that methanobactin is competitive with HA for Cu binding by forming strong 1:1 Cu-methanobactin complexes. Consequently, our results demonstrate that methanobactin can efficiently acquire Cu in organic-rich environments.

[Pippow's syndrome]. / Uber das Pippow-Syndrom.

For the first time since the initial report of aplasia of vertebral joints and brachydactyly occurring in a sibship, a similar family history of this rare dystostosis is presented. The following triad of symptoms is significant: a) hypoplasia of the laminae and of the articular and transverse processes of the vertebrae in the thoracolumbar region; b) cranial shift of the vertebral junctions; and c) brachydactyly. "Pippow's syndrome" and "Pippow's dysostosis" are suggested as possible names for this condition.