[Pheochromocytoma as dominant manifestation of v. Hippel-Lindau syndrome].

A diagnosis of von Hippel-Lindau syndrome was made in two families originating from the same part of the Black Forest but apparently unrelated. Nine affected persons (seven males and two females) had a total of 17 tumours: retinal angioma (4), haemangioblastoma of the CNS (1), and phaeochromocytoma (12). Three of the affected persons and eight of the tumours (six phaeochromocytomas, two retinal angiomas) were diagnosed by family screening. Phaeochromocytoma was diagnosed in eight persons; in four it was the only symptomatic lesion. After extensive diagnostic tests the phaeochromocytoma was the sole tumour in four. Despite severe symptoms the diagnosis of von Hippel-Lindau syndrome had not been made prior to the screening examinations because either the common aetiology of the tumour was not known or there was insufficient exchange of information between the two families.--It is recommended that in each case of phaeochromocytoma von Hippel-Lindau syndrome should be excluded so that lesions can be discovered early in other organs and in other affected family members. If the syndrome is present, annual examinations are indicated because of asynchronous and multi-focal tumour growth.


[Mercury concentration in the mouth mucosa of patients with amalgam fillings].

Mercury concentrations were measured in specimens of oral mucosa taken during oral surgery from 90 patients (53 men, 37 women, mean age 42 +/- 16 years); 30 of the patients had no amalgam fillings. All the mucosal specimens extended for at least 2-3 mm from the epithelium of the gingival margin and were clinically and radiologically normal. Thirteen patients without metallic fillings of any kind had mercury concentrations of 118.4 +/- 83.7 ng/g tissue, and in 17 patients with precious metal fillings but no amalgam the mean mercury concentrations were 144 +/- 290 ng/g tissue. Seventeen patients with 1-3 amalgam fillings had an average of 1975 +/- 4300 ng/g tissue and in 26 patients with 3-6 amalgam fillings the average concentration was 1158 +/- 2500 ng/g tissue. In 17 patients with more than six amalgam fillings the mean mercury concentration was 2302 +/- 5600 ng/g tissue. Although these results demonstrate a considerable degree of transfer of mercury from the amalgam fillings to the oral mucosa, it had not resulted in any clinically detectable mucosal lesions.


[Recurrent renal colic with passing of horny lamellae. A rare differential diagnosis of renal calculi].

A 64-year-old man reported left-sided renal colics recurring regularly every 5-10 months for the past 25 years. After a typical colic urinary sediment was found to contain brownish, flaky elastic material which histologically consisted of nucleus-free keratoid lamellae. Calcium concentration in serum and urine was normal, as were the serum parathormone (215 pg/l) and inorganic phosphate levels. The intravenous pyelogram revealed a polycyclicly circumscribed filling defect (15 x 20 mm) in the left renal pelvis. At ureteroscopy a lamellar brown-grey tumour was identified which arose from the medial wall of the pelvis. Histological examination demonstrated hyper- and parakeratotic hornified squamous epithelium without malignant degeneration. This finding suggested a cholesteatoma originating from squamous epithelial metaplasia. The tumour was removed endoscopically and the renal wall coagulated by laser, a procedure repeated after 3 months. The patient has been free of symptoms for 3 years.


[Leishmaniasis with multiple cutaneous nodules].

Six weeks after a holiday trip to Yugoslavia, a previously well 48-year-old man developed a reddish-livid, firm nodule, 0.5 cm in diameter, on the proximal joint of the right thumb. A similar nodule appeared nearby, as well as over the left patella. Eleven additional nodules occurred over the next 4 months. His general health remained good and physical examination merely noted the liver edge palpable 3 cm below the costal margin. The histology of one of the nodules showed a tuberculoid, plasma-rich inflammatory reaction reminiscent of leishmaniasis or brucellosis. No organisms were seen. Immunohistochemistry of a frozen section demonstrated Leishmania-associated antigens, and the Western-blot test was characteristic for leishmaniasis. No systemic treatment was undertaken because of likely alcoholic toxic liver damage. On local treatment with paromomycin-containing ointment the cutaneous nodules healed without scar within 3 months.


[Organ-preserving therapy in invasive bladder carcinoma].

With the aim of organ preservation, transurethral resection with subsequent radiotherapy (until 1985) or combined radio- and chemotherapy (since 1986) was undertaken as part of a prospective trial in 175 consecutive patients (137 men, 38 women; mean age 65 [31-90] years) with invasive bladder carcinoma, tumour stage T1-4 N0-3 M0. All patients had a transurethral resection, followed 2-6 weeks later by definitive radiotherapy at a dose of 50.4 Gy to the bladder in 28 fractions. 85 patients simultaneously with the radiotherapy received chemotherapy with cisplatin (25 mg/m2 daily) or carboplatin (65-75 mg/m2 daily) in the first and fifth weeks of radiotherapy. The 5-year survival rate for the whole group (including inoperable cases) was 50%. The survival rate as related to the T category was 53% for T1 (n = 26), 68% for T2 (n = 34), 45% for T3 (n = 94) and 22% for T4 (n = 17). 139 patients (79%) were left with a normally functioning bladder. Cystectomy was performed in 36 patients because of remaining tumour or recurrence after radiotherapy. Combined radio- and chemotherapy improved the histological remission rate, compared with an earlier control group with radiotherapy only, but it did not affect the survival rate. These data indicate that in advanced bladder carcinoma organ-preserving treatment with transurethral resection and definitive radiotherapy or combined radio- and chemotherapy can be successful.


[Complicated aneurysm of the splenic artery].

For 2 1/2 years after sustaining blunt trauma to the abdomen a 51-year-old woman had experienced episodes of pain, recently with throbbing, in the left upper quadrant. A smooth, circumscribed, painless tumour filling the left upper and mid-abdomen was palpable under the left costal margin. Ultrasound revealed a 12 x 11 cm space-occupying mass with cystic-fluid components, at first interpreted as a blood-containing pseudocyst. Computed tomography demonstrated a connection with the splenic artery. Digital subtraction angiography established the diagnosis of an aneurysm of the splenic artery arising immediately beyond its origin from the coeliac trunk. Splenectomy and resection of the aneurysm were performed. Total removal of the aneurysm was not undertaken because the dorsal aspect of the aneurysm wall was very thick and fused with the retroperitoneum. The postoperative course was unremarkable. The genesis of splenic aneurysm often remains unexplained. Its occurrence after blunt abdominal trauma is exceedingly rare.


[Perimyocarditis caused by Yersinia enterocolitica serotype 0:3].

Three days after the end of a bout of diarrhoea of 3 days' duration, a 19-year-old patient developed severe nocturnal thoracic pain unresponsive to isosorbitol dinitrate. There were no abnormal findings on physical examination, except a sweaty skin. SGOT (38 U/l), creatinine kinase (291 U/l, CK-MB 29 U/l) and lactate dehydrogenase (246 U/l) were all elevated. The ECG showed ST segment elevations in leads I, II, III, aVF and V1-V6 as well as negative terminal T waves in I, II, aVL, AVF and V3-V6, changes suggesting peri- and myocarditis. The Widal test gave a raised antibody titre (1:800) against Yersinia enterocolitica serotype O:3. Seven days later the immunoblot test demonstrated antibodies against the same organism, which was finally isolated from stool after 11 days. Treatment consisted of ciprofloxacin (500 mg twice daily for 14 days). All symptoms, as well as the biochemical and ECG abnormalities, quickly improved. The patient was discharged free of symptoms after 34 days.


[Decompression sickness as differential diagnosis in internal medicine emergency admissions].

Two men (aged 37 years--patient 1, and 26 years--patient 2), both in good health, had dived as a sport to a depth of 40 and 45 m, respectively, reportedly keeping to the prescribed decompression times on their ascent. Patient 1 immediately developed shortness of breath and pain in the chest, later neurological deficits in both legs, as well as faecal and urinary incontinence. Examination 60 h later revealed paraparesis, increased leg proprioceptor reflexes and paraesthesia below the 10th thoracic vertebra, with abnormal posterior column function. After recompression (hyperbaric oxygenation, 6 treatment sessions of 4 h each over 8 days, as prescribed in US Navy Table No. 6) the signs improved and two months later there were no deficits. Patient 2 developed 30 min after a similar dive painful, doughy swellings and redness over the upper ventral half of the thorax and both upper arms. All signs and symptoms disappeared after recompression treatment (hyperbaric oxygenation for 3 h), begun 28 h after the dive. Previously elevated levels for haemoglobin (18.5 g/dl), haematocrit (0.56) and red blood corpuscles (5.98 x 10(6)/microliters) returned to normal. The described neurological abnormalities are typical for type II, redness and joint pains for type I decompression sickness.


[The pharmacokinetics and bioavailability of acepromazine in the plasma of dogs].

Acepromazine is extensively used in veterinary practice. In dogs, it is used mainly as a preanaesthetic and sedative agent, without the knowledge of pharmacokinetic data in this species. We studied the disposition both after oral and intravenous administration. It was shown, that the sedative effect after an oral dose of 1.3-1.5 mg/kg lasted for about 4 hours. The elimination was slower after oral administration (half-life 15.9 h) than after i. v. injection (half-life 7.1 h). The bioavailability of the orally administered drug formulation averaged 20%. The calculation of the pharmacokinetic parameters was performed computer-aided, using conventional compartmental analysis and non-compartmental statistical moment analysis and the results were compared.


[In vitro studies of intestinal absorption and biotransformation of furazolidone].

The intestinal biotransformation and absorption of the nitrofuran furazolidone were investigated in isolated gut cells and in the isolated perfused gut. In case of inhibiting furazolidone metabolism by high oxygen tension almost equal concentrations of the parent compound were measured on the mucosal and serosal side of the perfused gut segments. Lowering oxygen supply in order to adjust it to physiological conditions caused a complete degradation of furazolidone in isolated gut cells. Accordingly, hardly any unchanged furazolidone was detected on the serosal side of the isolated perfused gut. An open-chain cyanometabolite was formed in both systems indicating a reductive metabolic process which induces highly reactive intermediates. This metabolite also reached the serosal side of the gut representing the systemic circuit. Thus, the low systemic bioavailability is due to the considerable intestinal metabolism rather than a limited absorption. Unknown metabolites will reach the systemic circuit, the toxic potential of which is still obscure. Independent of its metabolic degradation, thus probably due to its redox cycle furazolidone inhibited intestinal functions as e. g. the flow of water and the transport of sodium.


Atypical reactions to halothane in a subgroup of homozygous malignant hyperthermia(MH)-susceptible pigs: indication of a heterogenous genetic basis for the porcine syndrome.

Malignant hyperthermia (MH) is a pharmacogenetic disorder of skeletal muscle. In genetically susceptible pigs, MH can be induced by volatile, halogenated anaesthetics such as halothane. Within a series of pharmacological investigations, a fulminant MH could be induced in 59 of 66 homozygous halothane-susceptible pigs by a challenge with 3% halothane for 15 minutes. The typical MH was characterized by sudden appearance of tachycardia, muscle rigidity with typical extension of the hindlimbs, increase of body temperature, acidosis-caused by rapid increase of CO2 and lactate production-, hyperkalaemia and increased activity of creatine kinase (CK) and aspartate transaminase (AST). In seven homozygous MH-susceptible pigs, this typical MH could not be induced by halothane. These animals responded with sudden appearance of bradyarrhythmia and decrease of arterial pressure. In these MH-atypical pigs (MHA) neither the typical extension of hindlimbs nor a hyperthermia occurred. Compared to a group of 6 MH-susceptible pigs with typical reactions to halothane (MHS), the biochemical alterations were significantly retarded in MHA-pigs. These atypical reactions to halothane could be the effect of decreased cardiac output. Concerning the atypical reactions, we observed a familiar predisposition in MH-susceptible pigs. Although atypical reactions were not found in a group of homozygous halothane-nonsusceptible pigs (MHN), a possible explanation for atypical reactions could be a MH-independent halothane-susceptibility of the myocardium+ in MHA-pigs. On the other side the data may indicate that a primary defect in both the skeletal muscle and also the myocardium is involved in MH. The different reactions to halothane in MH-susceptible pigs could point to a genetic heterogeneity.


[Insufficient success in the treatment of epilepsy--mistakes in therapy or resistance to therapy?].

Frequently either no results or inadequate results are obtained in the therapy of canine and feline epilepsy. This is often not due to a primary resistance to therapy, but rather, caused by other factors and, above all, by mistakes made in therapeutic management. The possible causes of a faulty or insufficient treatment and the most common mistakes made in therapeutic regime are described. At the same time suggestions for an optimal course of therapy are given.


Acetylsalicylic acid and blood coagulation in the horse.

Equine blood may contain salicylic acid (SA) taken up as free acid or represents the metabolite of acetylsalicylic acid (ASA). To obtain information of SA in race horses we screened blood samples of trotting-horses routinely drawn to be analyzed for doping substances. The individual values determined followed a Gaussian distribution displaying a geometric mean of 19 ng SA per ml serum. A probit analysis revealed linear relationship (r = 0.995). Additional studies examined the antithrombotic efficacy of ASA in the horse. An oral dose of 300 mg ASA considerably elevated the bleeding time for more than 2 hours with concomitant SA serum levels between 800 and 1000 ng/ml. It is concluded that salicylate levels even below 1 microgram/ml serum bring about considerable pharmacologic effects such as prolongation of bleeding time, decrease in blood viscosity and possibly dilatation of blood vessels. These effects may improve the tissue supply with blood including oxygen.


[The loop diuretic bumetanide as a tool in physiology and pharmacology].

Loop diuretics are derivatives of 4-sulfamoylbenzoic acid, which derived originally from sulfonamides. Their diuretic effect is due to the inhibition of the Na-K-Cl-cotransport system in the distal part of Henle's loop. The compounds react with different affinity with the chloride binding site of the transporter. Bumetanide is among the most potent blockers with an IC50 of 0.2 microM. The compound was developed by P. W. FEIT, 1971; the saluretic response was described first by H. H. FREY 1972. Bumetanide has outgrown to become a tool for physiologists and pharmacologists in renal transport research. The compound has essentially contributed to the elucidation of the mechanisms of volume regulation of cells. Bumetanide is taken up into tubule cells and hepatocytes by active transport. The uptake in tubule cells ist mediated by an organic anion transporter, which is involved in the renal secretion of drugs. In the liver bumetanide is transporter by the bile acid carrier. The carrier is a multispecific drug transporter, too. It is not yet known, whether both drug transport systems contain identical membrane proteins. For this purpose bumetanide is currently used to investigate by photoaffinity labeling and functional expression cloning molecular principles of the drug elimination in kidney and liver.


[The metabolism of albendazole in the isolated perfused intestine of rats].

Pharmacokinetic studies on Albendazole after peroral administration demonstrate a rapid and complete biotransformation. The major metabolites Albendazole sulphoxide and -sulphone were detected in the plasma; the parent compound was only found sporadically at very low levels. These results indicate removal by the liver and/or the gut at first pass. After evidence is found that the liver has the capacity to sulphoxidize and to sulphonize Albendazole, biotransformation of the gut was examined using an isolated perfused rat gut model. A high-performance liquid chromatography method was used to simultaneously determinate Albendazole, -sulphoxide and -sulphone. Albendazole was biotransformed partly to Albendazole sulphoxide by the gut, whereby the metabolite but not the parent compound was absorbed. It is concluded, that the gut has the capacity to biotransform Albendazole. However, biotransformation is limited to the first step, the sulphoxidation.


[Effect of etretinate on the activity of intestinal disaccharidases].

The retinoid etretinate influences the proliferation and differentiation of epithelial cells. Therefore, the activity of disaccharidases maltase and sucrase was measured in duodenum and jejunum after oral retinoid application to female mice. The enzymes are localized in the brush border of differentiating mucosal cells. The etretinate dose ranged from 0.1 to 1 mg/kg. The treatment with etretinate induced a decrease of the duodenal and jejunal disaccharidase activity. A correlation between the influence in intestinal enzyme activity and undesired gastrointestinal side effects which were described by GOLD et al. (1988) is supposed.


[The problems of the so-called Arteria carotis externa (= ventralis) of the Anamniota. I. Comparative literature analysis].

The study discusses problems as related to the existence of a so-called A. carotis externa (= ventralis) in the Anamnia, and is based on the analysis of old and new literature. The facts presented are illustrated by several figures, demonstrating the organization pattern of branchial arteries and their various branches in adult animals as well as during the development of all types of branchial vessels. Summarizing the aspects involved, it can be concluded that an A. carotis ventralis does not exist, neither in reality nor as the first stage of an A. carotis externa. All of the efferent vessels coming from the 6 original branchial arteries, always arise from the respective A. branchialis efferens and contain oxygenated blood. As A. hypobranchialis lateralis and medialis these vessels supply the entire hypobranchial region, the floor of the mouth, and the heart. Moreover, a rostral prolongation of the Aorta ventralis is also not proven to exist during the ontogenesis of branchial arches.


[Electrophoretic studies of serum protein fractions in horses with laminitis].

The spectrum of serum proteins was evaluated in 46 horses affected with spontaneous laminitis and correlations between the severity of the disease and changes of the protein pattern were analyzed. The investigation was made in two groups; group A consisted of 21 horses of various breeds (warmblood, thoroughbred, standardbred) and group B of 25 ponys. Each group was subdivided according to the severity of the disease, using the OBEL-grade (OG) classification system. Serum proteins were separated by different one- and two-dimensional electrophoretic methods. Sera analysed by cellulose acetate electrophoresis showed a significant difference in the alpha 1-globulin fraction between OG II and OG IV affected horses. An increasing severity of the disease was correlated with a decrease of the alpha 1-globulins. The other protein fractions didn't show a uniform tendency. In group B there was a significant difference in the alpha 1-globulin fractions of OG II and OG III and in the beta 2-globulin fractions of OG I and OG II affected ponys. The acute phase proteins C3c, C4, Hp and fibronectin could be determined in a preliminary study in horse serum using the cross-reactivity of antibodies against the homologous human proteins.


[Biology, pathogenicity, diagnosis and control of Ancylostoma caninum].

Infections with Ancylostoma caninum are transmitted orally or percutaneously. The transmission of infectious stages with the milk of particular importance for the distribution of the species. It occurs during the dissemination of larvae that follows every infection as well as after reactivation of resting somatic larvae in the bitch at the end of the pregnancy. The galactogenic transmission of larvae occurs even when, due to existing immunity, no patent infections develop in the bitch. Immunity does not or only to a low extent influence impatient infections or the migration of reactivated somatic larvae. It also allows a limited reestablishment of a deposit of larvae in the bitch. Following percutaneous infection dermatitis occurs in the area of larval penetration and the lung is affected by migrating larvae. Intestinal stages of Ancylostoma caninum damage the host by ingestion of the mucosa of the small intestine and withdrawal of blood. Main symptoms of ancylostomiasis are a mucous haemorrhagic diarrhoea and anaemia, that become visible 8 to 10 days post infection. The examination for impatient infections with Ancylostoma caninum can be done by immunofluorescence and ELISA. With both methods antibodies against third stage larvae can be detected from the first or second week post infection onward. Patent infections with Ancylostoma caninum can easily be detected by faecal examination for the presence of the characteristic oval, thin-walled eggs containing few blastomeres. Galactogenic infections with Ancylostoma caninum can be prevented or reduced by a regular treatment of the bitch with albendazole, fenbendazole or oxfendazole during the activation of larvae in the last third of the pregnancy or by repeated treatment with ivermectin shortly before and after birth. To prevent patent infections, galactogenic infected puppies have to be treated early and repeatedly.


[Toxic effects in rabbits after immunization against the pyrrolizidine alkaloid retrorsine].

Six rabbits were immunized against the pyrrolizidine alkaloid retrorsin, conjugated to bovine serum albumin. Seven i.v. inoculations were distributed over a period of half a year. The total antigen dose differed between animals. Towards the end of the experiment all animals (except 2 receiving the lowest antigen dose) suffered from apathy, anorexia and loss of body weight. Pathologically these symptoms correlated well with liver cirrhosis, gradually dependent on the total antigen dose. Blood-chemical parameters were disparate and contradictory.


[Husbandry factors causing morphologic abnormalities in poultry meat (broilers)].

Zootechnical events affect the state of slaughtered poultry. Data from the literature are compiled. From this point of view monitoring of environmental parameters and morphological findings observed in the slaughterhouse can help in detecting faults in the fattening period. An approach like this would contribute to quality control in broiler meat production.


[The immunization of pheasants against Newcastle disease].

ND-Adsorbatvakzine "Dessau" and Lasovak are well effective and tolerated in pheasants as immuno-prophylactic methods against Newcastle disease infection. Lasovak produces higher titres of antibodies and better rates of protection. The antibodies are created quicker too and reduced more slowly. There is no correlation between the average of antibody level and rate of protection after experimental infection. Even if antibodies are not demonstrable in hemagglutination inhibition test there is still existing a satisfactory protection. After two vaccinations in the age of chickens in 3 to 4 weeks interval and repetition after always 16 weeks pheasants can be protected effectively for the rearing and breeding seasons.


[Effects of lowest levels of drugs--a contribution to homeopathy research].

After oral administration of homoeopathically prepared low-dose-amounts of Conium and Mercury phosphate to male Wistar rats enzymatic parameters were investigated in three subcellular compartments of the liver under blind conditions. 1. After seven single application of the substance amount referring to a D8 potency a maximum effect could be detected for both agents. 2. The relation between agent and magnitude of the provoked effect is not linear. 3. The importance of these results is discussed and integrated into a general context.


[Evaluation from a food regulatory aspect of tuberculous slaughtered cattle at the end of the 18th century--together with a study of the position of the veterinarian in public service at that time].

A decree of the Hannoverian sovereign GEORGE III passed in 1787 regarding the treatment of slaughtering cattle affected with tuberculous changes of the pleura is presented. Special emphasis is placed on the practice of food hygiene at that time and on the fact that the veterinarian was regarded an equal expert compared to the physician.


Asymmetrical retinoic acid synthesis in the dorsoventral axis of the retina.

An aldehyde dehydrogenase present at high levels in the dorsal retina of the embryonic and adult mouse was identified as the isoform AHD-2 known to oxidize retinaldehyde to retinoic acid. Comparative estimates of retinoic acid levels with a reporter cell line placed the retinas among the richest tissues in the entire body of the early embryo; levels in ventral retina, however, exceeded dorsal levels. Retinoic acid synthesis from retinaldehyde in the dorsal pathway was less effective than the ventral pathway at low substrate levels and more effective at high levels. The dorsal pathway was preferentially inhibited by disulfiram, while ventral synthesis was preferentially inhibited by p-hydroxymercuribenzoate. When protein fractions separated by isoelectric focusing were analyzed for retinoic acid synthesizing capacity by a zymography-bioassay, most of the synthesis in dorsal retina was found to be mediated by AHD-2, and ventral synthesis was mediated by dehydrogenase activities distinct in charge from AHD-2. Postnatally, levels of highest retinoic acid synthesis shifted from ventral to dorsal retina. In the adult retina, the dorsal pathway persisted, but the preferential ventral pathway was no longer detectable. Our observations raise the possibility that retinoic acid plays a role in the determination and maintenance of the dorsoventral axis of the retina, and that the morphogenetically significant asymmetry here lies in the spatial arrangement of synthetic pathways.


beta-D xyloside alters dermatan sulfate proteoglycan synthesis and the organization of the developing avian corneal stroma.

Corneal transparency is dependent upon the development of an organized extracellular matrix containing small diameter collagen fibrils with regular spacing, organized as orthogonal lamellae. Proteoglycan-collagen interactions have been implicated in the regulation of collagen fibrillogenesis and matrix assembly. To determine the role of dermatan sulfate proteoglycan in the development and organization of the secondary corneal stroma, its synthesis was disrupted using beta-D xyloside. The secondary corneal stroma contains two different proteoglycans, dermatan sulfate and keratan sulfate proteoglycan. beta-D xyloside interferes with xylose-mediated O-linked proteoglycan synthesis, and thus disrupts dermatan sulfate proteoglycan synthesis. Corneal keratan sulfate proteoglycan, a mannose-mediated N-linked proteoglycan, should not be altered. Biochemical analysis of corneas treated both in vitro and in ovo revealed a reduced synthesis of normally glycosylated dermatan sulfate proteoglycans and an increased synthesis of free xyloside-dermatan sulfate glycosaminoglycans. Keratan sulfate proteoglycan synthesis was unaltered in both cases. Corneal stromas were studied using histochemistry and electron microscopy after in ovo treatment with beta-D xyloside. The observed biochemical alterations in dermatan sulfate proteoglycans translated into disruptions in the organization of beta-D xyloside-treated stromas. There was a reduction in the histochemical staining of proteoglycans, but no alteration in collagen fibril diameter. In addition, focal alterations in collagen fibril packing, and a disruption of lamellar organization were observed in beta-D xyloside-treated corneas. These data suggest that dermatan sulfate proteoglycans are not involved in the regulation of corneal collagen fibril diameter, but are important in the fibril-fibril spacing as well as in lamellar organization, and cohesiveness.


A transgene containing lacZ is expressed in primary sensory neurons in zebrafish.

In order to screen for developmentally active chromosomal domains during zebrafish embryogenesis, we generated transgenic fish by microinjecting two different lacZ reporter constructs into fertilized eggs. Transgenic fish were screened among the progeny of injected fish (F0) crossed to non-injected fish. Groups of 15 to 20 progeny of each cross were tested for lacZ expression and/or transmission of injected sequences using PCR and Southern hybridizations. Progeny from 2 of 102 fish injected with supercoiled constructs containing Rous sarcoma virus promoter sequences showed apparently spatially regulated beta-galactosidase (beta-Gal) activity. However, we were not able to detect this reporter construct in DNA from fins of F1 fish. Injections of a linear reporter construct containing mouse heat-shock promoter sequences revealed transmission of injected sequences to F1 progeny in about 6% of cases (8 of 129 fish, tested with PCR). We found one lacZ-expressing line that showed a spatially and temporally restricted expression of lacZ and, therefore, features typical characteristics of "enhancer trap" lines. In this line, lacZ expression starts at 16 hours post-fertilization in trigeminal ganglion cells. At about 24 hours lacZ expression can be detected in trigeminal ganglion neurons and Rohon-Beard neurons, indicating that the development of these two cell types shows common features. The reporter gene has integrated as a single copy. The founder fish was mosaic: 19% of its offspring (3 of 16 tested animals) carried the reporter construct in their fins; about 51% (13 of 27 tested animals) of the progeny of F1 fish were beta-Gal positive indicating full hemizygosity.(ABSTRACT TRUNCATED AT 250 WORDS)


Spatial and temporal expression of an epithelial mucin, Muc-1, during mouse development.

The Muc-1 mucin is found as a transmembrane protein in the apical surface of glandular epithelia. To provide insight into possible functions, we have assessed the timing of expression and the distribution of the Muc-1 protein during mouse embryogenesis using three different techniques: RT-PCR, northern blots and immunohistochemistry. Our results indicate that Muc-1 expression correlates with epithelial differentiation in stomach, pancreas, lung, trachea, kidney and salivary glands. Once started, Muc-1 synthesis continually increases with time, mainly due to epithelial area growth. Our data suggest that expression of the Muc-1 gene is under spatial and temporal control during organogenesis. Although Muc-1 is present in different organs, its expression is not induced systemically, but according to the particular onset of epithelial polarization and branching morphogenesis of each individual organ. It is of particular interest that Muc-1 protein can be detected lining the apical surfaces of the developing lumens when the epithelium of these organs is still undergoing folding and branching, and glandular activity has not yet started. We speculate that Muc-1 may participate in epithelial sheet differentiation/lumen formation during early development of the organs known to express it. This speculation is based on: (1) the detection of Muc-1 expression early during organogenesis, (2) the defined apical localization in different epithelia, (3) the decrease in cell-cell interactions when Muc-1 protein is highly expressed and (4) the possible interaction of its cytoplasmic tail with the actin cytoskeleton. However, it remains to be established using in vitro systems, whether the temporal and local expression of the Muc-1 gene coincident with the morphogenetic events described here is relevant for the process.


Analysis of Xwnt-4 in embryos of Xenopus laevis: a Wnt family member expressed in the brain and floor plate.

This study characterizes the temporal and spatial expression during early Xenopus development of Xwnt-4, a member of the Wnt gene family. The Xwnt-4 protein contains all of the sequence motifs that are hallmarks of the Wnt gene family and is 84% identical to the mouse homolog, Wnt-4. The highest level of Xwnt-4 expression occurs during the early neurula stage of development although its expression persists throughout embryogenesis and can be found in the adult testis, brain and epithelium. Consistent with its localization to head and dorsal regions of microdissected embryos, the expression of Xwnt-4 is enhanced in anterodorsalized embryos resulting from treatment with LiCl, and the expression of Xwnt-4 is suppressed in UV-ventralized embryos that lack anterior neural tissue. These results suggested that expression of Xwnt-4 is dependent on the induction of neural tissue. This idea was tested using induction experiments with dorsal or ventral ectoderm from a stage 10 embryo, recombined with dorsal marginal zone mesoderm from the same embryo. Recombinant tissue and ectoderm alone were cultured until stage 14, when Xwnt-4 expression was assayed using Northern analysis. In the recombinant assay, Xwnt-4 expression does not occur in the uninduced ectoderm but is expressed in both the dorsal and ventral recombinants. Xwnt-4 expression in neural ectoderm was confirmed in isolated, induced neural ectoderm, dissected away from the dorsal mesoderm, in a stage 12.5 embryo. Whole-mount in situ hybridization confirmed the dissection studies and demonstrated that Xwnt-4 transcripts are expressed in the dorsal midline of the midbrain, hindbrain and the floor plate of the neural tube. Collectively, the data indicate that Xwnt-4 is a unique member of the Wnt family whose expression is dependent on neural induction. The specific pattern of expression following neural induction suggests that Xwnt-4 plays a role in the early patterning events responsible in the formation of the nervous system in Xenopus.


Isolation and expression of two novel Wnt/wingless gene homologues in Drosophila.

Wingless (wg), the Drosophila homologue of the mouse Wnt-1 proto-oncogene, is a segment polarity gene essential in each segment for normal Drosophila development. We here report the isolation of two novel Drosophila Wnt homologues, DWnt-2 and DWnt-3, and thus the existence of a Wnt/wingless gene family in Drosophila. DWnt-2 and DWnt-3 map to chromosome 2 position 45E and chromosome X position 17A/B, respectively. DWnt-2 and DWnt-3, like the other known Wnt genes, encode amino-terminal signal peptides suggesting that the gene products are secreted proteins. The putative translation product of DWnt-2 and the carboxy-terminal half of the deduced DWnt-3 product are both rich in conserved cysteine residues. In comparison with other Wnt gene products, mostly about 40 x 10(3) relative molecular mass, the DWnt-3 protein has an extended amino terminus and a long internal insert, and its predicted relative molecular mass is 113 x 10(3). The expression patterns of these two Wnt/wg homologues are dynamic during Drosophila embryogenesis. The distribution of DWnt-2 transcripts is predominantly segmented, with the additional presence of transcripts in the presumptive gonads. Transcripts of both DWnt-2 and DWnt-3 appear to be associated with limb primordia in the embryo and may therefore specify limb development. DWnt-3 is also expressed in mesodermal and neurogenic regions. The distribution of DWnt-3 transcripts in cells of the central nervous system (CNS) during Drosophila embryogenesis suggests that DWnt-3 could be involved in CNS development.


Analysis of glia cell differentiation in the developing chick peripheral nervous system: sensory and sympathetic satellite cells express different cell surface antigens.

To identify and analyse precursor cells of neuronal and glial cell lineages during the early development of the chick peripheral nervous system, monoclonal antibodies were raised against a population of undifferentiated cells of E6 dorsal root ganglia (DRG). Non-neuronal cells of E6 DRG express surface antigens that are recognized by four monoclonal antibodies, G1, G2, GLI 1 and GLI 2. The proportion of non-neuronal cells in DRG that express the GLI 1 antigen is very high during ganglion formation (80% at E4) and decreases during later development (15% at E14). GLI 2 antigen is expressed only on a minority of the cells at E6 and increases with development. The G1 and G2 antigens are expressed on about 60-80% of the cells between E6 and E14. All cells that express the established glia marker O4 are also positive for the new antigens. In addition, it was demonstrated that GLI 1-positive cells from early DRG, which are devoid of O4 antigen, could be induced in vitro to express the O4 antigen. Thus, the antigen-positive cells are considered as glial cells or glial precursor cells. Surprisingly, the antigen expression by satellite cells of peripheral ganglia is dependent on the type of ganglion: antigens G1, G2 and GLI 1 were not detectable on glial cells of lumbosacral sympathetic ganglia and GLI 2 was expressed only by a small subpopulation. These results demonstrate an early immunological difference between satellite cells of sensory DRG and sympathetic ganglia.(ABSTRACT TRUNCATED AT 250 WORDS)


Gynandromorphs of Drosophila suggest one common primordium for the somatic cells of the female and male gonads in the region of abdominal segments 4 and 5.

In mosaic gonads of gynandromorphs of Drosophila, the amount of female and the amount of male somatic tissues add up to roughly one unit. This suggests that the somatic component of the gonads in males and females derives from a single common primordium, i.e. testes and ovaries appear to be homologous. Fate-mapping places this primordium ventrally of the sternites into the mesodermal region of the fourth and fifth abdominal segment. This location is corroborated by the observation that defects in and around abdominal segment 4 and absence of the gonads are strongly correlated in animals damaged by the mutation osk301. Gonads were mosaic with a frequency of 10.5% which indicates that the gonadal primordium originates from about 10 progenitor cells, and together with other evidence, suggests that these progenitor cells are located within a single segment (or parasegment).


PDGF receptors in the rat CNS: during late neurogenesis, PDGF alpha-receptor expression appears to be restricted to glial cells of the oligodendrocyte lineage.

Using in situ hybridization, we have visualized cells in the rat central nervous system (CNS) that contain mRNA encoding the platelet-derived growth factor alpha receptor (PDGF-alpha R). After embryonic day 16 (E16), PDGF-alpha R mRNA appears to be expressed by a subset of glial cells, but not by neurons. The temporal and spatial distribution of PDGF-alpha R+ cells, together with 125I-PDGF binding studies on subsets of glial cells in vitro, suggests that PDGF-alpha R may be expressed predominantly, or exclusively, by cells of the oligodendrocyte-type-2 astrocyte (O-2A) lineage. This conclusion is supported by the fact that the numbers of PDGF-alpha R+ cells in developing and adult optic nerves correlate well with independent estimates of the number of O-2A progenitor cells in the nerve at equivalent ages. Small numbers of PDGF-alpha R+ cells are present in the brain at E16, at which time they are found outside the subventricular germinal zones, suggesting that these cells do not express PDGF-alpha R until after, or shortly before they start to migrate away from the subventricular layer towards their final destinations. Reduced numbers of PDGF-alpha R+ cells persist in the adult CNS. PDGF-alpha R is also expressed strongly in the meningeal membranes and choroid plexus, and in the inner limiting membrane of the retina.


Bone morphogenetic protein 4: a ventralizing factor in early Xenopus development.

The mesoderm of amphibian embryos such as Xenopus laevis arises through an inductive interaction in which cells of the vegetal hemisphere of the embryo act on overlying equatorial and animal pole cells. Three classes of 'mesoderm-inducing factor' (MIF) that might be responsible for this interaction in vivo have been discovered. These are members of the transforming growth factor type beta (TGF-beta), fibroblast growth factor (FGF) and Wnt families. Among the most potent MIFs are the activins, members of the TGF-beta family, but RNA for activin A and B is not detectable in the Xenopus embryo until neurula and late blastula stages, respectively, and this is probably too late for the molecules to act as natural inducers. In this paper, we use the polymerase chain reaction to clone additional members of the TGF-beta family that might possess mesoderm-inducing activity. We show that transcripts encoding Xenopus bone morphogenetic protein 4 (XBMP-4) are detectable in the unfertilized egg, and that injection of XBMP-4 RNA into the animal hemisphere of Xenopus eggs causes animal caps isolated from the resulting blastulae to express mesoderm-specific markers. Surprisingly, however, XBMP-4 preferentially induces ventral mesoderm, whereas the closely related activin induces axial tissues. Furthermore, the action of XBMP-4 is 'dominant' over that of activin. In this respect, XBMP-4 differs from basic FGF, another ventral inducer, where simultaneous treatment with FGF and activin results in activin-like responses. The dominance of XBMP-4 over activin may account for the ability of injected XBMP-4 RNA to 'ventralize' whole Xenopus embryos. It is interesting, however, that blastopore formation in such embryos can occur perfectly normally. This contrasts with embryos ventralized by UV-irradiation and suggests that XBMP-4-induced ventralization occurs after the onset of gastrulation.


Cultured dermal papilla cells induce follicle formation and hair growth by transdifferentiation of an adult epidermis.

Adult rat pelage follicle dermal papilla cells induced follicle neogenesis and external hair growth when associated with adult footpad skin epidermis. They thus demonstrated a capacity to completely change the structural arrangement and gene expression of adult epidermis--an ability previously undocumented for cultured adult cells. Isolation chambers ensured that de novo follicle formation must have occurred by eliminating the possibility of cellular contributions, and/or inductive influences, from local skin follicles. These findings argue against previous suggestions of vibrissa follicle specificity, and imply that the potential for hair follicle induction may be common to all adult papilla cells.


Activation of the easter zymogen is regulated by five other genes to define dorsal-ventral polarity in the Drosophila embryo.

The product of the Drosophila easter gene, a member of the trypsin family of serine proteases, must be more active ventrally than dorsally to promote normal embryonic polarity. The majority of the easter protein in the embryo is present in the unprocessed zymogen form and appears to be evenly distributed in the extracellular space, indicating that the asymmetric activity of wild-type easter must arise post-translationally. A dominant mutant form of easter that does not require cleavage of the zymogen for activity (ea delta N) is active both dorsally and ventrally. The ea delta N mutant bypasses the requirement for five other maternal effect genes, indicating that these five genes exert their effects on dorsal-ventral patterning solely by controlling the activation of the easter zymogen. We propose that dorsal-ventral asymmetry is initiated by a ventrally-localized molecule in the vitelline membrane that nucleates an easter zymogen activation complex, leading to the production of ventrally active easter enzyme.


DVR-4 (bone morphogenetic protein-4) as a posterior-ventralizing factor in Xenopus mesoderm induction.

Establishment of mesodermal tissues in the amphibian body involves a series of inductive interactions probably elicited by a variety of peptide growth factors. Results reported here suggest that mesodermal patterning involves an array of signalling molecules including DVR-4, a TGF-beta-like molecule. We show that ectopic expression of DVR-4 causes embryos to develop with an overall posterior and/or ventral character, and that DVR-4 induces ventral types of mesoderm in animal cap explants. Moreover, DVR-4 overrides the dorsalizing effects of activin. DVR-4 is therefore the first molecule reported both to induce posteroventral mesoderm and to counteract dorsalizing signals such as activin. Possible interactions between these molecules resulting in establishment of the embryonic body plan are discussed.


A maternal factor, OZ-1, activates embryonic transcription of the Xenopus laevis GS17 gene.

We describe the identification of an enhancer sequence and a sequence-specific DNA-binding protein required for developmental expression of the Xenopus laevis GS17 gene. Using microinjection of recombinant plasmids into fertilized frog eggs, we have shown that a 14 base pair CT-rich sequence element, normally located about 700 bases upstream of the GS17 promoter, is sufficient to activate transcription of a heterologous reporter gene in gastrula stage embryos. This regulatory element has been called the OZ sequence. Sequences closely related to OZ are located in the promoter regions of several other genes expressed during Xenopus development. Extracts prepared from Xenopus embryos show the presence of a DNA-binding factor, OZ-1, that specifically recognizes the OZ sequence. Mutations within the OZ element that abolish OZ-1 binding also abolish enhancer activity. The OZ-1 factor contains at least two proteins of approximate M(r) 76 x 10(3) and 100 x 10(3). The sequence-specific binding activity accumulates during oogenesis and remains present at approximately constant levels throughout early development.


The neural tube/notochord complex is necessary for vertebral but not limb and body wall striated muscle differentiation.

The aim of this work was to investigate the role played by the axial organs, neural tube and notochord, on the differentiation of muscle cells from the somites in the avian embryo. Two of us have previously shown that neuralectomy and notochordectomy is followed by necrosis of the somites and consecutive absence of vertebrae and of most muscle cells derived from the myotomes while the limbs develop normally with muscles. Here we have focused our attention on muscle cell differentiation by using the 13F4 mAb that recognizes a cytoplasmic antigen specific of all types of muscle cells. We show that differentiation of muscle cells of myotomes can occur in the absence of notochord and neural tube provided that the somites from which they are derived have been in contact with the axial organs for a defined period of time, about 10 hours for the first somites formed at the cervical level, a duration that progressively reduces caudalward (i.e. for thoracic and lumbar somites). Either one or the other of the two axial organs, the neural tube or the notochord can prevent somitic cell death and fulfill the requirements for myotomal muscle cell differentiation. Separation of the neural tube/notochord complex from the somites by a surgical slit on one side of the embryo gave the same results as extirpation of these organs and provided a perfect control on the non-operated side. A striking finding was that limb and body wall muscles, although derived from the somites, differentiated in the absence of the axial organs. However, limb muscles that develop after excision of the neural tube started to degenerate from E10 onward due to lack of innervation. In vitro explantation of somites from different axial levels confirmed and defined precisely the chronology of muscle cell commitment in the myotomes as revealed by the in vivo experiments.


Synaptic basal lamina contains a signal for synapse-specific transcription.

Nuclei in the synaptic region of multinucleated skeletal myofibers are transcriptionally distinct, since acetylcholine receptor genes are transcribed at a high rate by these nuclei, but not by nuclei elsewhere in the myofiber. Although this spatially restricted transcription pattern is presumably imposed by the motor nerve, the continuous presence of the nerve is not required, since synapse-specific transcription persists after denervation. These results suggest either that a transcriptional signal persists at synaptic sites after nerve terminals have degenerated, or that a transcriptional pattern in the myofiber, once established, is stable in the absence of a nerve-derived signal. To distinguish between these possibilities, we denervated muscle and damaged the myofibers and specialized cells located near synaptic sites, and then studied transcription of an acetylcholine receptor gene in myofibers that regenerated in their original basal lamina sheaths, but remained denervated. We show that synapse-specific transcription is re-induced in these regenerated myofibers, and we conclude that a signal for synapse-specific transcription is stably maintained in the synaptic basal lamina.


Ventral ectoderm of Xenopus forms neural tissue, including hindbrain, in response to activin.

The peptide growth factor Activin A has been shown to induce complete axial structures in explanted blastula animal caps. However, it is not understood how much this response to activin depends upon early signals that prepattern the ectoderm. We have therefore asked what tissues can be induced in blastula animal caps by activin in the absence of early dorsal signals. Using whole-mount in situ hybridization, we compare the expression of three neural markers, N-CAM, En-2 and Krox-20 in activin-treated ectoderm from control and ventralized embryos. In response to activin, both normal and ventralized animal caps frequently form neural tissue (and express N-CAM) and express the hindbrain marker Krox-20. However, the more anterior marker, En-2, is expressed in only a small fraction of normal animal caps and rarely in ventralized animal caps; the frequency of expression does not increase with higher doses of activin. In all cases En-2 and Krox-20 are expressed in coherent patches or stripes in the induced caps. Although mesoderm is induced in both control and ventralized animal caps, notochord is found in response to activin at moderate frequency in control caps, but rarely in ventralized animal caps. These results support the idea that in the absence of other signals, activin treatment elicits hindbrain but not notochord or anterior neural tissue; and thus, the anterior and dorsal extent of tissues formed in response to activin depends on a prior prepatterning or previous inductions.


Activin can generate ectopic axial structures in chick blastoderm explants.

We have recently shown that activin can induce the formation of axial structures from chick blastulae and that activin beta-B is transcribed, in the hypoblast of the chick, at the same stage that axial mesoderm is being induced. It was not clear, however, whether activin was merely allowing the central epiblastic cells to express a differentiated phenotype for which they were already prepared. This report shows that activin-containing medium (ACM) can act as an instructive inductor, which can change the fate of competent cells and bring about the formation of an ectopic embryonic axis. Furthermore, we show data that suggest that during normal development only one axis is obtained as a result of a carefully controlled inhibitory process.


Developmental expression of the Xenopus int-2 (FGF-3) gene: activation by mesodermal and neural induction.

We have used a probe specific for the Xenopus homologue of the mammalian proto-oncogene int-2 (FGF-3) to examine the temporal and spatial expression pattern of the gene during Xenopus development. int-2 is expressed from just before the onset of gastrulation through to prelarval stages. In the early gastrula, it is expressed around the blastopore lip. This is maintained in the posterior third of the prospective mesoderm and neuroectoderm in the neurula. A second expression domain in the anterior third of the neuroectoderm alone appears in the late gastrula, which later resolves into the optic vesicles, hypothalamus and midbrain-hindbrain junction region. Further domains of expression arise in tailbud to prelarval embryos, including the stomodeal mesenchyme, the endoderm of the pharyngeal pouches and the cranial ganglia flanking the otocyst. It is shown, by treatment of blastula ectoderm with bFGF and activin, that int-2 can be expressed in response to mesoderm induction. By heterotypic grafting of gastrula ectoderm into axolotl neural plate, we have also demonstrated that int-2 can be expressed in response to neural induction. These results suggest that int-2 has multiple functions in development, including an early role in patterning of the anteroposterior body axis and a later role in the development of the tail, brain-derived structures and other epithelia.


The somitogenetic potential of cells in the primitive streak and the tail bud of the organogenesis-stage mouse embryo.

The developmental potency of cells isolated from the primitive streak and the tail bud of 8.5- to 13.5-day-old mouse embryos was examined by analyzing the pattern of tissue colonization after transplanting these cells to the primitive streak of 8.5-day embryos. Cells derived from these progenitor tissues contributed predominantly to tissues of the paraxial and lateral mesoderm. Cells isolated from older embryos could alter their segmental fate and participated in the formation of anterior somites after transplantation to the primitive streak of 8.5-day host embryo. There was, however, a developmental lag in the recruitment of the transplanted cells to the paraxial mesoderm and this lag increased with the extent of mismatch of developmental ages between donor and host embryos. It is postulated that certain forms of cell-cell or cell-matrix interaction are involved in the specification of segmental units and that there may be age-related variations in the interactive capability of the somitic progenitor cells during development. Tail bud mesenchyme isolated from 13.5-day embryos, in which somite formation will shortly cease, was still capable of somite formation after transplantation to 8.5-day embryos. The cessation of somite formation is therefore likely to result from a change in the tissue environment in the tail bud rather than a loss of cellular somitogenetic potency.


Developmental regulation of villin gene expression in the epithelial cell lineages of mouse digestive and urogenital tracts.

The expression of villin, an actin-binding protein and major structural component of the brush border of specialized absorptive cells, was studied during mouse embryogenesis. We show that the ontogeny of villin expression is limited to the epithelial cell lineages of the digestive and uro-genital tracts and accounts for the tissue-specific expression observed in adult mice. This spatiotemporal pattern of villin expression is distinctive in sequence, intensity, regional distribution and polarization. During the development of the primitive gut, villin is faintly and discontinuously expressed in the invaginating foregut but it is expressed in every cell bordering the hindgut pocket. Later, villin expression increases along the developing intestine and concentrates in the brush border of the epithelium bordering the villi. In gut derivatives, villin is present in liver and pancreas primordia but only biliary and pancreatic cells maintain a faint villin expression as observed in adults. In the urogenital tract, mesonephric tubules are the first mesodermal derived structures to express villin. This expression is maintained in the ductuli efferents, paradidymis and epoöphoron. Villin then appears in the proximal metanephric tubules and later increases and concentrates in the brush border of the renal proximal tubular epithelial cells. Thus villin expression can be considered as an early marker of the endodermal cell lineage during the development of the digestive system. Conversely, during the development of the excretory and genital system, villin is only expressed after the mesenchyme/epithelium conversion following the appearance of tubular structures. These observations emphasize the multiple levels of regulation of villin gene activity that occur during mouse embryogenesis and account for the strict pattern of tissue-specific expression observed in adults. In the future, regulatory elements of the villin gene may be used to target the early expression of oncogenes to the digestive and urogenital tracts of transgenic mice.


Expression pattern of Motch, a mouse homolog of Drosophila Notch, suggests an important role in early postimplantation mouse development.

The Notch gene of Drosophila encodes a large transmembrane protein involved in cell-cell interactions and cell fate decisions in the Drosophila embryo. To determine if a gene homologous to Drosophila Notch plays a role in early mouse development, we screened a mouse embryo cDNA library with probes from the Xenopus Notch homolog, Xotch. A partial cDNA clone encoding the mouse Notch homolog, which we have termed Motch, was used to analyze expression of the Motch gene. Motch transcripts were detected in a wide variety of adult tissues, which included derivatives of all three germ layers. Differentiation of P19 embryonal carcinoma cells into neuronal cell types resulted in increased expression of Motch RNA. In the postimplantation mouse embryo Motch transcripts were first detected in mesoderm at 7.5 days post coitum (dpc). By 8.5 dpc, transcript levels were highest in presomitic mesoderm, mesenchyme and endothelial cells, while much lower levels were detected in neuroepithelium. In contrast, at 9.5 dpc, neuroepithelium was a major site of Motch expression. Transcripts were also abundant in cell types derived from neural crest. These data suggest that the Motch gene plays multiple roles in patterning and differentiation of the early postimplantation mouse embryo.


Ectopic sensory neurons in mutant cockroaches compete with normal cells for central targets.

The cercus of the first instar cockroach, Periplaneta americana, bears two filiform hairs, lateral (L) and medial (M), each of which is innervated by a single sensory neuron. These project into the terminal ganglion of the CNS where they make synaptic connections with a number of ascending interneurons. We have discovered mutant animals that have more hairs on the cercus; the most typical phenotype, called "Space Invader" (SI), has an extra filiform hair in a proximo-lateral position on one of the cerci. The afferent neuron of this supernumerary hair (SIN) "invades the space" occupied by L in the CNS and makes similar synaptic connections to giant interneurons (GIs). SIN and L compete for these synaptic targets: the size of the L EPSP in a target interneuron GI3 is significantly reduced in the presence of SIN. Morphometric analysis of the L afferent in the presence or absence of SIN shows no anatomical concomitant of competition. Ablation of L afferent allows SIN to increase the size of its synaptic input to GI3. Less frequently in the mutant population, we find animals with a supernumerary medical (SuM) sensillum. Its afferent projects to the same neuropilar region as the M afferent, makes the same set of synaptic connections to GIs, and competes with M for these synaptic targets. The study of these competitive interactions between identified afferents and identified target interneurons reveals some of the dynamic processes that go on in normal development to shape the nervous system.


Developmental regulation of chromatin composition during mouse embryogenesis: somatic histone H1 is first detectable at the 4-cell stage.

We have examined the distribution of histone H1 in oocytes and preimplantation embryos of the mouse, using a polyclonal antibody raised against the histone H1 subtypes present in somatic cells. Immunofluorescence and immunoblotting analyses failed to detect somatic histone H1 in germinal vesicle (GV)-stage oocytes. In contrast, somatic histone H1 was detectable by immunofluorescence in the nuclei of GV oocytes previously injected with histone H1 as well as the nuclei of ovarian granulosa cells, and by immunoblotting in 8-cell embryos. 1- and 2-cell embryos examined by immunofluorescence did not contain detectable somatic histone H1. At the early 4-cell stage (54-56 hours post-hCG), 5 of 52 embryos contained somatic histone H1 in one or more nuclei. By the late 4-cell stage (66-68 hours post-hCG), however, 58 of 62 embryos contained somatic histone H1. In 8-cell embryos, morulae and blastocysts, all nuclei contained somatic histone H1 in every case. When embryos were exposed to the transcriptional inhibitor, alpha-amanitin, beginning at the late 2-cell stage, they cleaved to the 4-cell stage but fewer than 10% developed histone H1 immunoreactivity. When treatment began at the early 4-cell stage, the embryos that remained at the 4-cell stage in the presence of the drug developed histone H1 immunoreactivity in half of the cases. Embryos that reached the 5- to 8-cell stage in the presence of the drug developed histone H1 immunoreactivity in every case.(ABSTRACT TRUNCATED AT 250 WORDS)


orthodenticle activity is required for the development of medial structures in the larval and adult epidermis of Drosophila.

Lethal alleles of orthodenticle (= otd) cause abnormalities in the embryonic head that reflect an early role in anterior pattern formation. In addition, otd activity is required for the development of the larval and adult epidermis. Clonal analysis of both viable and lethal alleles shows that the adult requirement for otd is restricted to medial regions of certain discs. When otd activity is reduced or removed, some medial precursor cells produce bristles and cuticle characteristic of more lateral structures. Similar medial defects are observed in the larval epidermis of embryos homozygous for lethal otd alleles. Antibodies to otd recognize a nuclear protein found at high levels in the medial region of the eye antennal discs, the leg discs, the genital discs and along the ventral midline of the ventral epidermis of the embryo. These results suggest that the otd gene product is required to specify medial cell fates in both the larval and adult epidermis.


Platelet derived growth factor (PDGF) stimulates development of bovine embryos during the fourth cell cycle.

In vitro produced, 2-cell bovine embryos were cultured in serum-free medium supplemented with various combinations of growth factors to test the hypothesis that these polypeptide factors are able to signal preimplantation development. The developmental arrest that occurs during the 8-cell stage with typical culture methods might be relieved by a growth factor-dependent mechanism that would stimulate expression of the embryonic genome, thereby mimicking events that occur in vivo in the oviduct during the fourth cell cycle (8- to 16-cell stage). Subsequently, other growth factors might promote compaction and blastulation, processes which normally occur in the uterus. The effects of growth factors on early embryos were evaluated using phase contrast microscopy to monitor progression to the 8-cell stage, completion and duration of the fourth cell cycle, and blastocyst formation. Platelet derived growth factor (PDGF) promoted development beyond the 16-cell stage in 39.1% of the 2-cell embryos examined in all experiments. The duration of the fourth cell cycle among these embryos was approximately 26 hours. During development after the 16-cell stage, PDGF reduced the proportion of embryos bastulating from 12.7% to 5.8%; in contrast, transforming growth factor alpha (TGF alpha), acting during the same developmental time period, increased the proportion of embryos blastulating from 8.6% to 40.6%. These results, using serum-free medium, indicated that PDGF signalled completion of the fourth cell cycle. TGF alpha, and perhaps basic fibroblast growth factor (bFGF), promoted blastulation of 16-cell embryos during subsequent culture.


Differential expression of gap junction mRNAs and proteins in the developing murine kidney and in experimentally induced nephric mesenchymes.

The expression of three gap junction (GJ) proteins, alpha 1 (Cx43), beta 1 (Cx32), and beta 2 (Cx26), and their transcripts were examined during the ontogeny of the mouse and rat kidney. These proteins were expressed in two non-overlapping patterns. The alpha 1 GJ protein was first observed in mesenchymal cells in the 12-day mouse kidney. By day 14 and thereafter, the alpha 1 protein was detected in the transient S-shaped bodies, but not in the podocytes of the maturing glomeruli. After birth the antigen was retained in a small subset of secretory tubules. The beta 1 and beta 2 GJ proteins were similar in their developmental patterns. They were first detected in a small subset of secretory tubules in the subcortical zone of day 17 embryos. These tubules were identified by immunohistochemical markers to be proximal. At birth, practically all proximal tubules expressed the two antigens. This analysis of GJ proteins was consistent with the results of S1 nuclease protection assays showing that, while the alpha 1 mRNA appeared early during kidney development and declined around birth, the two beta mRNAs appeared later and became intensified during the last days of intrauterine development. In experimentally induced metanephric mesenchymes, a transient expression of the alpha 1 GJ protein was seen during the segregation of the tubular anlagen. beta 1 and beta 2 GJ proteins were not detected in such induced mesenchymes cultivated up to 7 days. These observations provide evidence for the cell-specific utilization of different GJ genes during different stages of kidney organogenesis. The alpha 1 gene is activated during the early segregation of the secretory tubule and might contribute to its compartmentalization, while the beta 1 and beta 2 gene products are not detected until advanced stages of development. The latter gene products might be correlated with the physiological activity of the proximal tubules in vivo, as they are not expressed in experimentally induced tubules detectable with markers for proximal tubules.


The torpedo (DER) receptor tyrosine kinase is required at multiple times during Drosophila embryogenesis.

The torpedo (DER) gene of Drosophila, which encodes a receptor tyrosine kinase of the EGF receptor subfamily, is essential for oogenesis, embryogenesis and imaginal disc development. To gain insight into the nature of the signals transduced by the torpedo product, we have characterized the gene's loss-of-function phenotype in the embryo. Through the induction of germline clones, we provide a genetic demonstration that maternal torpedo product does not contribute to zygotic development. Thus, the embryonic lethal phenotypes examined accurately reflect the consequences of eliminating all gene activity from the zygote. Temperature-shift experiments with the conditional allele topIF26 show that torpedo is required at two distinct times during embryonic development: the gene is first needed for germband retraction and for the production of anterior, posterior and ventral cuticle, then later for the secretion of ventral denticles. Since denticle formation can be severely disrupted in topIF26 animals without affecting cuticle production, the early and late requirements for torpedo appear to be functionally unrelated. torpedo, therefore, is required at multiple times in the development of the ventral epidermis, and may transduce qualitatively different signals. Since the early requirement for torpedo correlates with the first visible defect in embryonic development, increased cell death in the amnioserosa, cephalic ectoderm and ventral epidermis, the abnormalities in cuticle production and germband shortening seen in the mutant may be secondary consequences of a primary defect in cell viability. Given that the onset of cell death in torpedo embryos is not preceded by any obvious defects in mitogenesis, the establishment of cell identities or the maintenance of gene expression, it is possible that torpedo transduces a signal necessary for cell survival per se during early embryogenesis. During late embryogenesis, torpedo may mediate the reception of a second signal which regulates ventral epidermal cell differentiation.


A developmentally regulated switch in neuronal responsiveness to NCAM and N-cadherin in the rat hippocampus.

Monolayers of control 3T3 fibroblasts and 3T3 cells expressing transfected NCAM or N-cadherin have been used as a culture substratum for rat hippocampal neurons. Both NCAM and N-cadherin are expressed in the hippocampus through embryonic day 17 (E17) to postnatal day 4 (PND4); however, whereas E17 neurons responded to transfected NCAM by extending considerably longer neurites, PND4 neurons responded very poorly. The converse was true for responsiveness to N-cadherin. These data demonstrate a switch in neuronal responsiveness to NCAM and N-cadherin in the developing hippocampus. NCAM-dependent neurite outgrowth from E17 neurons was largely dependent on the presence of alpha 2-8-linked polysialic acid (PSA) on neuronal NCAM. NCAM-dependent neurite outgrowth could be fully inhibited by pertussis toxin or a combination of L- and N-type calcium channel antagonists thus providing direct evidence concerning the nature of the second messenger pathway activated in primary neurons by cell adhesion molecules (CAMs).


Use of the accelerating rotarod for assessment of motor performance decrement induced by potential anticonvulsant compounds in nerve agent poisoning.

The accelerating rotarod was used to assess motor performance decrement in rats after administration of candidate anticonvulsant compounds (acetazolamide, amitriptyline, chlordiazepoxide, diazepam, diazepam-lysine, lorazepam, loprazolam, midazolam, phenobarbital and scopolamine) against nerve agent poisoning. All compounds were tested as the commercially available injectable preparation except for diazepam-lysine and loprazolam, which are not FDA approved. A peak effect time, as well as a dose to decrease performance time by 50% from control (PDD50), was determined. The calculated PDD50 (mumol/kg) values and peak effect times were midazolam, 1.16 at 15 min; loprazolam, 1.17 at 15 min; diazepam-lysine, 4.17 at 30 min; lorazepam, 4.98 at 15 min; diazepam, 5.27 at 15 min; phenobarbital, 101.49 at 45 min; chlordiazepoxide, 159.21 at 30 min; scopolamine, amitriptyline and acetazolamide did not demonstrate a performance decrement at any of the doses tested. The PDD50 values were compared with doses which have been utilized against nerve agent-induced convulsions or published ED50 values from standard anticonvulsant screening tests (maximal electroshock [MES] and subcutaneous pentylenetetrazol [scMET]). The results suggest that at anticonvulsant doses against nerve agents, all the benzodiazepines and phenobarbital have the potential to cause a performance decrement, whereas candidate anticonvulsants of the non-benzodiazepine or non-barbiturate type would not be expected to demonstrate this effect on motor performance. It is concluded that compounds such as acetazolamide, amitriptyline and scopolamine offer alternatives to the highly decrementing benzodiazepines and phenobarbital and should be further tested as anticonvulsant candidates against nerve agent intoxication.


Ninety-day toxicity study of chloral hydrate in the Sprague-Dawley rat.

Male and female Sprague-Dawley rats were administered drinking water containing 300, 600, 1200, or 2400 mg/L chloral hydrate for 90 days. A control group received distilled water only. No animals died during the study and no differences were observed in body weight gain or food and water consumption, except for males at the highest-dose level. Minor treatment-related effects were observed for organ weights and hematological parameters and these did not appear to be of toxicological significance. Some indications of toxicity were evident in the 2400 mg/L male group (equivalent to 168 mg/kg-day) including a significant decrease in food and water consumption and in weight gain. In addition, histopathological examination of these animals revealed an apparent increase in the incidence of focal hepatocellular necrosis. Increases in AST, ALT, and LDH, which occurred at several dose levels in males, but particularly at 200 mg/L, are consistent with the hepatocellular necrosis of minimal to mild severity diagnosed by microscopic examination. These liver changes, except for sporadic enzyme changes, were not seen in the female rats which actually consumed higher doses of chloral hydrate (e.g., 288 mg/kg-day at 2400 mg/L). On the basis of the mild liver toxicity (histopathological and clinical) observed in males at the highest doses (168 mg/kg-day), the no observed adverse effect level (NOAEL) for oral exposure of rats to chloral hydrate for 90 days is considered to be 96 mg/kg-day (600 mg/L).


Altered activity of hepatic mixed function oxidase, cytochrome P-450 and glutathione-S-transferase by styrene in rat fetal liver.

The effect of in utero exposure to styrene 200 or 400 mg/kg/day orally was studied on mixed function oxidase activities, cytochrome P-450 and glutathione contents and on the glutathione-S-transferase activity in rat fetal liver. Activities of aminopyrene-N-demethylase, aniline hydroxylase, aryl hydrocarbon hydroxylase and the cytochrome P-450 contents were significantly decreased in the fetal liver. A significant decrease in the glutathione contents and the glutathione-S-transferase activity was also observed in the liver of the fetuses of styrene exposed animals. The current data show that prenatal exposure to styrene could adversely affect the developing biotransformation process.


2,4-Dichlorophenoxyacetic acid action on in vitro protein synthesis and its relation to polyamines.

The effect of 2,4-dichlorophenoxyacetic acid (2,4-D) on the in vitro synthesis of proteins was studied in Chinese hamster ovary cells. A remarkable inhibition of the synthesis of proteins was observed when cells grew for 24 h in presence of 1 mM 2,4-D. This effect was reversed by adding 0.1 mM of the three polyamines (putrescine, spermidine and spermine) to the cultured cells. The mRNA is not altered, indicating that the 2,4-D action is located at a different locus, which may be the ribosomes. From these studies, one can speculate that the alterations in the protein synthesis may be a consequence of the effect of 2,4-D on the polyamine metabolism.


Effect of preperfusion of lead and aminophylline on digoxin cardiotoxicity.

An attempt has been made to investigate the cardiotoxicity of an interaction of Lead acetate (LA), Aminophylline (APH) and Digoxin (DGN), employing an isolated frog heart preparation. While DGN-Cardiotoxicity was potentiated by LA-preperfusion, it was antagonized by APH-preperfusion as revealed by data reflecting the mean DGN perfusion time (Sec) and mean DGN exposure (microgram/10 mg heart weight) for cardiac arrest. In an experimental group involving interaction of LA, DGN and APH, preperfusion of APH has significantly diminished but not fully abolished LA-induced potentiation of DGN-cardiotoxicity. On the other hand, perfusion of APH after LA resulted not only in annulment of LA-induced potentiation but also in an eventual residual protective effect of APH. It was striking that simultaneous preperfusion of APH and LA led to exacerbation of LA-induced potentiation. The results of this interaction study involving two widely prescribed cardioactive drugs, are considered to be of immense pharmaco-toxicological interest.


Incidence of acoustic neuromas.

The annual incidence of diagnosed acoustic neuromas in Denmark during two 7-year periods from June 1976 to June 1990 was compared, collecting all operated and non-operated tumors from the entire country. During the first period 278 tumors were diagnosed with an annual incidence of 38 tumors or 7.8 tumors per million per year. During the second period the annual incidence rose to 48 tumors and 9.4 tumors per million per year. There was a significant decrease of extrameatal tumor size from 33 to 26 mm and diminishing of giant tumors.


Otitis media and chronic middle ear effusion in the asthmatic pediatric patient.

In a retrospective study, a high incidence of otitis media and chronic middle ear effusion was recognized in pediatric patients with allergies, in particular, asthma. Five hundred and nineteen cases were examined to see if significant correlations could be made between asthma and 1) the development of otitis media, 2) the placement of multiple tubes, and 3) the incidence of mucoid otitis media, or "glue ear." The results of this preliminary report indicate that otitis media in the asthmatic patient seems to be a reflection of a disease affecting the entire mucociliary system in the respiratory tract and that this information should be used when making a prognosis for an asthmatic patient.


Medullary hemorrhage causing vertigo and gaze nystagmus.

Brainstem hematomas carry a poor prognosis. There are rare reports of excellent outcome with hemorrhages in the midbrain. We report a 43-year-old woman with vertigo and minimal neurological symptoms, whose symptoms were initially mistaken for "inner ear disease," but subsequent investigations revealed a medullary hemorrhage. Recovery was complete within two weeks. While rare, medullary hemorrhage should be considered in the differential diagnosis of vertigo.


The external rhinoplasty approach for rhinologic surgery.

The technique of external rhinoplasty has enjoyed a renaissance over the last ten years, primarily for cosmetic and functional septorhinoplasty, and we have found this to be an effective method for nasal reconstruction. Moreover, we have recognized the versatility of this approach for a variety of rhinologic problems and have utilized it for transsphenoidal hypophysectomy, sphenoidotomy, unilateral choanal atresia, septal perforation, nasal valvuloplasty and rhinophyma. We describe our technique and the rationale for employing it. We conclude that the enhanced exposure provided by the cutaneous decortication of the nose facilitates surgery of both the soft tissues and the supportive architecture of the nose.


False-positive cytologic findings in Warthin's tumor: a report of two cases.

In two adults who smoked cigarettes, fine needle aspiration of a neck mass suggested squamous cell carcinoma. However, both lesions proved to be benign Warthin's tumor with metaplasia of the epithelial lining mimicking squamous cell carcinoma. Several clinical and histologic features can alert the physician to this finding. Awareness of the possibility of a false-positive cytologic report with Warthin's tumor is important for all physicians treating tumors of the head and neck.


Head and neck manifestations of Wegener's granulomatosis.

Sixteen of 17 patients with Wegener's granulomatosis were found to have head and neck involvement. Rhinitis and/or nasal obstruction were the most common presenting symptoms. On initial clinical examination, paranasal sinus involvement was observed in 11 patients, ear involvement in 7 and subglottic stenosis in 2 patients. One patient presented with a large and rapidly widening ulcer on the lateral pharyngeal wall. Diagnosis was often difficult and severe delay in diagnosis occurred in 7 patients. In recent years tests for ANCA appeared to be extremely useful.


Granular cell tumor of the larynx: report of two pediatric cases.

Granular cell tumors are uncommon neoplasms of the head and neck that usually involve the tongue. The larynx is an atypical site of involvement in adults and a rare site in children. We report two cases of subglottic granular cell tumors, one in a 10-year-old boy and the other in a 6-year-old girl. Although both were initially misdiagnosed as having asthma, radiologic, laryngoscopic, and histologic evaluation of the obstructions eventually furnished the correct diagnosis. The patients were successfully treated by surgical excision of their subglottic masses. The history, presentation, pathologic findings, management, and prognosis of this rare pediatric laryngeal tumor are explored.


[Quantitative topographic characterization of the myoelectric activity distribution of the masseter muscle: mapping of spectral EMG parameters].

A new method for quantitative characterization of myoelectrical masseter activity distribution by mapping of spectral EMG-parameters is described. The surface electromyograms of M. masseter were monopolarly recorded (16 channels). On the basis of registered EMG intervals (512 ms) the spectral EMG power of several frequency bands was calculated (Fast Fourier Transformation). The spectral EMG parameters between the 16 electrode positions were estimated by linear interpolation (4-nearest neighbours algorithm). Afterwards the spectral EMG parameters were fitted in a grey-tone or colour scale with 10 intervals. The so obtained EMG activity maps ("EMG-Maps") permit a quantitative-topographic characterization of myoelectrical masseter activity during different functional load procedures. The frequency range which is to consider in masseter surface-EMG investigations encloses frequencies between 15 and 500 Hz. The topography of EMG activation pattern of M. masseter is only described in a comprehensive manner when the electrode array consists of 16 electrodes and more. During defined motor tasks like clenching with controlled forces the reproducibility of EMG-Maps which respect to the topography of EMG activity pattern is very high. The absolute values of spectral EMG power as well as power changes of selected band ranges during clenching correlate to the extent of chewing forces.


[Mapping spectral EMG parameters of the masseter muscle in normal probands under defined loads].

In 20 healthy volunteers 16-channel surface electromyograms were monopolarly recorded from the right and left masseter muscle during defined functional conditions (force-constant bite, right and left hand side, 196, 333, 530 N chewing force, during a compensation of a load directed from a frontal or a lateral position to the mandible (20, 49, 69 N), during rest position of the mandible). The EMG curves were quantified by the calculation of spectral EMG-parameters (FFT). With respect to the muscle a topographic oriented representation of the myoelectrical activity was realised by a mapping of spectral EMG-parameters. The monopolarly recorded EMG activities significantly differed between the 16 electrode positions (topographic EMG distribution pattern). During the several examination conditions of the masseter muscle different topographic distribution pattern of the myoelectrical activity were found. Moreover, the total EMG power between the muscle functions differed too. The level of the load influenced the spectral EMG power as well as, partly, the topographic EMG distribution pattern.


[Computer-assisted analysis of the electromyogram for routine clinical use].

A computerized EMG analysis system implemented on an MS-DOS computer was developed explicitly for clinical routine usage. It incorporates analysis of interference pattern as well as of motor unit action potentials (MUAPs). Key features of MUAP analysis are the automatic segmentation and parameterization of the EMG signal and the automatic assignment of MUAPs to motor units. Determination of muscle activity is based on threshold detection of the signal's first derivative, leading to the definition of a MUAPs central component. Its parameters (length, amplitude, maximal steepness, area between curve and base-line, area between first derivative and base-line, number of turns etc.) are used when comparing MUAPs. The automatic assignment of MUAPs to motor units was implemented as an iterative procedure. MUAPs are compared to a reference MUAP and eventually assigned to it if their parameters are sufficiently similar. For such a group of MUAPs the most representative MUAP is determined which is then used as new reference MUAP in the next iteration step. Most important for clinical routine usage are simple handling, speed and the clearly arranged presentation of results. The system allows for interactive modification of MUAP assignment as well as start and end points of every MUAP. Analysis results may be displayed on the screen and printed, giving the user a quick impression of the muscle under study. Thus this method meets basic requirements for computer assisted decision making in differential diagnosis.


[A comparative study of the sensory conduction velocity of the sural nerve using surface and needle electrodes].

In 18 healthy persons aged 22-71 years and 17 patients suffering from clinically defined polyneuropathy the NCV of the sural nerve was measured both by antidromic technic recorded by surface electrodes and by orthodromic technique recorded by needle electrodes. Stimulation was done by bipolar surface electrodes in all cases. The skin temperature was warmed up to the minimum of 35 degrees C. The results showed in both groups a highly significant correlation of the NCV measured by antidromic and orthodromic technique. With increasing age the NCV decreased, but this was not significant. In all healthy persons sensory nerve potentials could be recorded with both techniques. In polyneuropathy missing of sensory potentials was higher in patients investigated by the antidromic technique than by orthodromic. For clinical practice measurement of NCV in sural nerve using antidromic technique should be preferred because of its simpler and faster achieving, its lower discomfort for the patient and avoiding risk of infection. However in case of missing nerve potentials, orthodromic investigation using needle electrodes for recording should be added.


[Is the origin of the F-wave dependent on the magnitude of the motor unit?].

It is still unknown why only few motor units (MUs) generate F-waves in response to supramaximal stimulation of a motor nerve. Therefore we investigated whether the F wave production might depend on MU-size. According to the size principle of Henneman we used the twitch force as indirect measure of MU-size. MU twitch force was determined applying the technique of intramuscular microstimulation of single motor axons. 127 MUs were analysed in 16 normal subjects. F-waves were observed in 35 MUs (27%). It was found that MUs of different sizes produced F-waves with approximately the same probability. Obviously size is not a relevant factor for the capability of a MU to produce F-waves. Only the few very large MUs of a pool may have an increased tendency to produce F-waves because four of five MUs with extremely large twitch forces (> 70 mN) generated F-waves.


[Evoked potentials following cerebral ischemia in the rat: the effect of the stimulus frequency].

EEG and somatosensory evoked potentials were recorded in anesthetized rats before and up to 24 h after 30 min of global forebrain ischemia. Before ischemia, SEP (sweep time 1000 ms) included primary (N25P50) components and late potentials of low amplitude. During ischemia, SEP and EEG were isoelectric. During postischemic recirculation SEP evoked by stimulation at 1.0 Hz remained severely suppressed for 24 h, although long-latency potentials (> 100 ms) recovered. Using a very low stimulation frequency of 0.1 Hz, late components strongly increased in amplitude and the overall evoked activity in the averaged post-stimulus-EEG reached 90% of control. These results demonstrate that the SEP evoked at very low stimulation frequency may serve as an early indicator of functional brain recovery after prolonged cerebro-circulatory arrest.


[Electroencephalography and cranial computed tomography in a posterior infarct].

In this study we interpreted the electroencephalograms of 50 patients, all suffering from a cerebral infarction occurred in the circulation area of A. cerebri posterior with or without involvement of thalamic structures. The diagnosis was established by clinical findings and via CT-examinations. Besides the EEG-findings which always occurred in the occipital region we found alterations which exceeded the above mentioned posterior disorder of the brain function. In most cases these have been bilateral paroxysmal disorders projected into the temporal regions but lateralized to the region of the existing posterior infarction. If we had CT-examinations of cerebral infarctions in the circulation area of A. cerebri posterior without an involvement of thalamic structures, there was no projected activity which exceeded the posterior disorder in EEG. In all cases with the additional affection of thalamic structures in CT the bilateral paroxysmal EEG disorders into the temporal region were found.


[Automatic (computer-assisted) EEG analysis in comparison with visual EEG analysis in patients following minor cranio-cerebral trauma (a follow-up study)].

The study was designed to examine the clinical applicability and use of computer-assisted EEG-analysis in comparison to visual EEG-analysis in patients with minor head injuries. For this in 31 patients the following examinations were performed within the first 24 hours, one, three and eight weeks after traumatization: EEG, neurological examination and standardized evaluation of subjective complaints. The EEG was analysed visually as well as computer-assisted. The results were compared to the neurological findings and subjective complaints. Reversible posttraumatic EEG-changes were observed in 50% of all patients. The results of computer-analysis and visual analysis were equivalent in respect to baseline-activity (as one of the main characteristic EEG-features). Furthermore, based on computer-assisted analysis a discriminant function is provided, which is of diagnostic and prognostic value in the single patient. We conclude that the computer-assisted EEG-analysis can be a useful alternative in EEG-routine diagnosis after minor head injuries.


[Dextrose and vigilance: the effect of dextrose on the spectro-analytic parameters of pharmaco-EEG].

In a randomized single-blind cross-over-design the effect of 15 g dextrose was investigated against placebo with 48 healthy subjects at two different days each. The quantitative pharmaco-EEG was recorded occipitocentral at the left side (O1-Cz) under vigilance controlled conditions and then under resting conditions (three minutes each). Having measured its baseline it was repeated six times every 20 minutes starting 10 minutes after the application of the substance. After the administration of dextrose a stabilization of vigilance could be seen in the EEG by the following differences of statistical significance (p < = 0.05) between dextrose and placebo under resting recording conditions: In the first control (14.-16. minute post) there was a significant decrease of the relative power in the delta and in the theta range combined with an increase of alpha 2. In the second control (34.-36. minute post) there was a significant decrease of relative power in the theta range and significant increase in the alpha 1 range. In the third control (54.-56. minute post) and later on no effects of dextrose were left in the pharmaco-EEG. The significant differences in the first and second control have to be interpreted as follows: After the administration of dextrose the level of vigilance was increased compared to the placebo group.


Current and future trends in wound healing.

New adjuncts to outpatient wound care focus on diminishing infection rates and improving the speed and effectiveness of laceration repair. This article provides an overview of growth factors, proteolytic enzymes, topical antimicrobial agents, and new materials that facilitate wound closure. Also, the pathophysiology of surface wound repair is summarized.


Wound evaluation and cleansing.

The approach to wound management in the Emergency Department does not differ from that used in evaluating other complaints. This consists of a problem-directed history and physical examination. The history should probe for host and wound factors that increase the risk of a poor outcome. The examination should emphasize a search for the involvement of underlying structures. Appropriate cleansing remains the foundation for good wound management. Until a rapid inexpensive test is available to identify wounds with low bacterial counts, the clinician should assume that all wounds have bacterial loads capable of causing infection. Therefore, most wounds should be cleansed by irrigation with at least 200 mL of normal saline. Larger quantities or 1% povidone-iodine solution may be used in wounds that have high wound or host risk factors. Wound exploration should occur in a well-lit environment and combine good hemostasis with appropriate analgesia and anesthesia.


Suture materials and mechanical after care.

Proper wound closure necessitates a familiarity with the various types of materials and the indications and contraindications of the many techniques available. Proper wound dressing and after-care instruction ensure optimal results and help minimize complications.


Sedation and analgesia.

The control of pain and the alleviation of anxiety are integral components in the management of soft tissue injuries in the Emergency Department. Pharmacologic agents utilized for analgesia and sedation must possess properties favorable for emergency department use. This article reviews the pharmacologic approach to patients who require sedation and/or analgesia for the management of a soft tissue injury in the Emergency Department.


Local anesthetics.

Emergency physicians often rely on the use of local anesthetic agents to relieve patient discomfort, and research continues in an effort to develop new agents with improved anesthetic qualities. Eventually, a nontoxic, rapidly acting agent may become available that could provide profound anesthesia of long duration when applied topically to intact skin or wounds. Until the "perfect" agent is developed, physicians can help the patient by making knowledgeable choices regarding local anesthetic techniques. By choosing topical agents when appropriate and buffering agents to be infiltrated, using courteous techniques of injection, and being cognizant of potential adverse reactions, the physician can turn a potentially unpleasant and frightening situation for the patient into a positive experience that promotes satisfaction and cooperation.


Emergency management of dog and cat bite wounds.

Most dog and cat bite injuries are minor wounds that require only local wound care as well a patient evaluation for tetanus and rabies postexposure immunoprophylaxis. For larger wounds, primary or delayed primary closure can be performed safely where indicated. When antimicrobial agents are necessary, inexpensive penicillins or cephalosporins are adequate for initial therapy. Large-scale, prospective, controlled clinical studies are needed to define further the role of prophylactic antimicrobial therapy for uninfected wounds.


Soft tissue infections.

Infections in soft tissues present with one or more of the cardinal signs of infections; however, presence of these signs may indicate manifestation of a deep systemic infection or of a noninfectious process. One of the earliest determinations to be made is whether the problem is likely to require patient admission or referral to another specialty. Only then is the primary management clear.


The rational use of antimicrobial agents in simple wounds.

The wounds in most patients presenting to the Emergency Department will heal uneventfully and do not require the use of antimicrobial agents. Specific indications for antimicrobial use include simple wounds in patients with lymphedema, orthopedic prostheses, or in those patients prone to bacterial endocarditis. Relative indications include high-risk wounds in compromised hosts, wounds contaminated with feces, saliva, or vaginal secretions, or wounds clinically infected at the time of presentation. More important than antimicrobial administration is the commitment to aggressive, timely wound care. Pitfalls in therapy center around the injudicious use of antimicrobial agents. Such therapy does not give the physician permission to close wounds that should be left open or to give less than optimal wound care. Physicians should be keenly aware of the fact that antimicrobial use is not innocuous. The economic burden and potential for adverse side effects must be weighed against the fact that the wounds in 90% to 95% of patients presenting to the Emergency Department will heal without the use of antimicrobial agents.


Detection and management of foreign bodies in soft tissue.

The discovery and management of foreign bodies in soft tissue are challenging problems for emergency physicians. History, physical examination, and thorough wound exploration serve as the screening test for the presence of foreign bodies. Various radiographic studies can be performed to confirm the diagnosis, to identify the object's composition and shape, and to determine its approximate location in the tissues. Once the object is discovered, the clinician must weigh the potential harm of the foreign body in its current location against the risks of attempting removal.