Context-dependent neural responses to minor notes in frontal and temporal regions distinguish musicians from nonmusicians.

Musical training is required for individuals to correctly label musical modes using the terms "major" and "minor," whereas no training is required to label these modes as "happy" or "sad." Despite the high accuracy of nonmusicians in happy/sad labeling, previous research suggests that these individuals may exhibit differences in the neural response to the critical note-the note (the third of the relevant key) that defines a melody as major or minor. The current study replicates the presence of a late positive component (LPC) to the minor melody in musicians only. Importantly, we also extend this finding to examine additional neural correlates of critical notes in a melody. Although there was no evidence of an LPC response to a second occurrence of the critical note in either group, there was a strong early right anterior negativity response in the inferior frontal gyrus in musicians in response to the first critical note in the minor mode. This response was sufficient to classify participants based on their musical training group. Furthermore, there were no differences in prefrontal asymmetry in the alpha or beta bands during the critical notes. These findings support the hypothesis that musical training may enhance the neural response to the information content of critical note in a minor scale but not the neural response to the emotional content of a melody.

Unexplained bleeding as primary clinical complaint in dogs infected with Angiostrongylus vasorum.

INTRODUCTION: Unexplained bleeding was the primary clinical complaint in 15 dogs diagnosed with A. vasorum and was observed in the mouth, as external bleeding, as large subcutaneous hematoma, as hemoptysis, in the brain, post ovariectomy, as epistaxis, in the anterior ocular chamber and on a tracheal intubation tube. In 8 dogs the cause of bleeding initially was suspected to be a minor trauma or a surgical complication, and various surgical approaches had been undertaken to eliminate the problem. In only 3 dogs respiratory signs were observed before the bleeding prompted referral. The median time elapsed between the first recognized clinical signs attributed to A. vasorum until diagnosis was 2 weeks (range1 day to 4 months). Four dogs died, 3 on the day of admission and 1 dog 4 days after admission. Suspected causes of death were respiratory failure and cerebral hemorrhage in 2 dogs each. Four dogs had been pre-treated with NSAIDs; of these, 2 dogs developed severe hemoptysis (1 died), 1 dog developed brain hemorrhage (and died), and 1 dog developed a large subcutaneous hematoma with marked anemia. Bleeding at various sites may be the only recognized abnormality in A. vasorum infection. Without a high index of suspicion, the diagnosis and appropriate therapy may be delayed to the point of a fatal outcome. Tests of coagulation were quite variable and the cause of bleeding likely multifactorial.

INTRODUCTION: Un saignement inexplicable a été le symptôme clinique primaire chez 15 chiens chez lesquels une infestation à A. vasorum a été diagnostiquée par la suite. Ces saignements ont été observés sous forme d'hémorragies dans la gueule, de saignements externes, de gros hématomes sous-cutanés, d'hémoptysie, de saignements cérébraux, de saignements abdominaux après ovariectomie, de saignements dans la chambre antérieure de l'oeil ou sur le trachéotube lors d'intubations. Chez 8 chiens, on a supposé que le saignement était initialement dû à un petit traumatisme ou à une complication opératoire et diverses mesures chirurgicales ont été prises pour résoudre le problème. Chez trois chiens, des symptômes respiratoires ont été observés avant que le saignement n'amène à l'envoi dans un centre de référence. Le temps moyen écoulé entre les premiers symptômes causés par A. vasorum et le diagnostic était de 2 semaines (1 jour à 4 mois). Quatre chiens sont décédés, 3 le jour de leur arrivée et un 4 jours plus tard. Les causes probables de la mort étaient dans deux cas une déficience respiratoire et dans deux une hémorragie cérébrale. Quatre chiens avaient été traités précédemment avec des AINS; deux d'entre eux ont développé une hémoptysie massive et un en est mort, un chien a présenté une hémorragie cérébrale fatale et le dernier a développé un volumineux hématome sous-cutané avec une anémie massive. Un saignement à un endroit quelconque peut être la seule anomalie constatée lors d'une infestation par A. vasorum. Si on n'a pas d'importants soupçons de cette affection, le diagnostic et le traitement adéquat peuvent être tellement retardés qu'une issue fatale survient. La cause pathophysiologique des hémorragies est vraisemblablement multifactorielle.

[Placement of intraluminal stents for treating tracheal collapse in dogs]. / Implantation intraluminaler Stents zur Behandlung des Trachealkollaps beim Hund.

Tracheal collapse is a progressive disease particularly of small breed dogs. In the terminal stage, when dyspnea becomes the dominating sign and is no longer manageable with medical treatment, a surgical procedure is necessary. With increasing frequency intraluminal tracheal stents are implanted minimal-invasively. In individual animals this is a lifesaving procedure, leading to immediate elimination of dyspnea. In most dogs cough for some time has to be anticipated as the stent acts as a foreign body, but severe complications like excessive formation of granulation tissue, stent migration or stent fracture are rare. Stents represent an attractive treatment modality for tracheal collapse in dogs with dyspnea.

A novel assistive therapy chair to improve trunk control during neurorehabilitation: Perceptions of physical therapists and patients.

A prototype assistive therapy chair (T-Chair) that induces exercise stimuli to improve trunk control and standing and walking early after stroke has been developed. The aim of this study was to assess its usability in a rehabilitation setting. Eleven physical therapists (PTs) integrated the T-Chair into the therapy programs of 15 patients post stroke. Each patient performed on average four individual therapy sessions on the T-Chair under the PTs' supervision. Usability was assessed using questionnaires, therapy diaries and focus group interviews with PTs'. Among PTs', 64% had generally a positive view on the T-Chair. Physical therapists recognized the potential for unsupervised therapy. Generally, patients reacted positively and enjoyed training. The T-Chair has the potential to become an adequate training tool for patients with an intermediate trunk control after stroke. Further development and usability testing are required to provide a therapeutic device allowing for an intensive therapy early post stroke.

[Natural infection with Angiostrongylus vasorum: characterisation of 3 dogs with pulmonary hypertension]. / Natürliche Angiostrongylus vasorum Infektion: Charakterisierung des Krankheitsbildes bei drei Hunden mit pulmonärer Hypertonie.

Pulmonary hypertension (PH), together with its accompanying clinical signs and underlying causes, e.g. pulmonary thrombosis, are more and more recognized as an important clinical entity also in dogs. This article characterizes the clinical picture of 3 dogs with PH caused by natural infection with Angiostrongylus vasorum. All 3 dogs were of small breeds ( < 10 kg), the age at the time of diagnosis was 1, 2 and 11 years. Clinically, dyspnea and exercise intolerance were the predominating signs, 2 dogs developed hemoptysis, 1 dog developed right sided congestive heart failure. Severe arterial hypoxemia (PaO2 41 - 53 mmHg) reflected the severity of pulmonary parenchymal and vascular damage. Severe hyperglobulinemia (59 und 88 g/l) in two dogs implicated a long lasting infection. Anthelmintic treatment in 2 dogs resulted in quick clinical, radiographic and echocardiographic normalization. PH is the consequence of multiple causes and pathomechanisms, and the recognition of PH is primarily of differential diagnostic relevance. Prognosis and therapy in cases with PH mainly depend on the underlying cause, rather than on the PH and on its degree.

[Infectious canine hepatitis in 4 dogs in Switzerland]. / Hepatitis contagiosa canis Infektion bei 4 Hunden in der Schweiz.

Infectious canine hepatitis in 4 Dogs in Switzerland. Four dogs presented with nonspecific symptoms of lethargy, vomiting, diarrhea, fever and weakness. Laboratory results were consistent with hepatopathy and disseminated intravascular coagulation. Three dogs died, one survived. In the three deceased dogs, a diagnosis of infectious canine hepatitis (ICH) was made based on histological findings and positive immunhistochemistry results for canine adenovirus-1 (CAV-1). In the surviving dog, an antemortem diagnosis of ICH was determined via positive polymerase chain reaction results from blood, occular, nasal and preputial discharge as well as from urine. Since the introduction of widespread vaccination, the incidence of CAV-1 infection in dogs is low. However, the disease has not been eradicated and should be considered when clinical signs consistent with ICH are present.

Long-term estrogen exposure of whitefish Coregonus lavaretus induces intersex but not Lake Thun-typical gonad malformations.

A high prevalence of gonad morphological variations has been observed in whitefish Coregonus lavaretus from Lake Thun (Switzerland). To clarify the role of endocrine disruption as a possible cause of the gonad alterations, whitefish were reared in a long-term laboratory experiment under exposure to 17 beta-estradiol (E2). Fish were fed from first-feeding until 3 yr of age at a daily rate of 0 (control), 0.5 or 50 microg E2 kg(-1) fish. E2 exposure resulted in a time- and concentration-dependent increase of prevalence and intensity of intersex gonads, i.e. gonads that macroscopically appeared as either testis or ovary but microscopically contained both male and female germ cells. Four types of intersex could be distinguished: Types 1 and 2 were composed of mainly male tissue, with Type 1 containing single oocytes and Type 2 displaying an ovary-like lamellar structure of the tissue. In Type 3, an increased percentage of the tissue was occupied by female germ cells, while in Type 4, the majority of the gonad tissue consisted of female germ cells. Chronic E2 exposure additionally resulted in a concentration-dependent shift of the sex ratio towards females, a reduced condition factor, retarded gonad growth together with delayed maturation of germ cells, and elevated levels of hepatic vitellogenin mRNA. However, Lake Thun-typical alterations of gonad morphology were not induced by chronic E2 exposure. The results provide evidence that estrogen-active compounds unlikely play a role in the etiology of gonad malformations in Lake Thun whitefish.

Back to basics: the development of a simple, homogenous, two-component dry-powder inhaler formulation for the delivery of budesonide using miscible vinyl polymers.

It was hypothesised that formulating a dry-powder inhaler (DPI) using a refined, smooth grade of lactose, without fines and a polymer coated drug microparticle should produce an homogeneous formulation in which aerosolization behaviour could be modified. Hence, the aim of this study was to develop a simple two component polymer coated-budesonide/lactose blend in which the drug microparticle adhesive forces could be optimised by modifying the drug coating in order to improve aerosolization from a DPI. Budesonide microparticles (1.83 +/- 0.03 microm) were coated with the vinyl polymers by adsorption and then spray-dried. The drug was blended with three different types of lactose, checked for uniformity of mixing and loaded into Pulvinal devices. The median volume particle size of all but one of the polymer coated microparticles remained below 4 microm after spray-drying and the content uniformity for all the blends >96%. Coating the budesonide with 0.01% poly(vinyl alcohol) increased the fine particle fraction (FPF) in the next generation impactor (NGI) from 29.1 +/- 0.7% to 52.8 +/- 1.0% and reduced the force of adhesion from 410 +/- 182 to 241 +/- 82 nN with smooth lactose. This illustrates that vinyl polymers could effectively modify adhesive interactions without the need for ternary components such as fines.

Serum concentrations of cortisol and cortisone in healthy dogs and dogs with pituitary-dependent hyperadrenocorticism treated with trilostane.

The serum concentrations of cortisol and cortisone were measured in 19 healthy dogs and in 13 dogs with pituitary-dependent hyperadrenocorticism (PDH) before and one hour after an injection of synthetic adrenocorticotropic hormone (ACTH). In the dogs with pdh, the cortisol and cortisone concentrations were measured before and after one to two weeks and three to seven weeks of treatment with trilostane. The dogs with PDH had significantly higher baseline and poststimulation concentrations of cortisol and cortisone, and higher baseline cortisol:cortisone ratios than the healthy dogs. During the treatment with trilostane, the poststimulation cortisol, the baseline and poststimulation cortisone concentrations, and the baseline and poststimulation cortisol:cortisone ratios decreased significantly. The decrease in poststimulation cortisone was significantly smaller than the decrease in cortisol.

Evaluation of cortisol precursors for the diagnosis of pituitary-dependent hypercortisolism in dogs.

The serum concentrations of cortisol, 17alpha-hydroxypregnenolone, 17alpha-hydroxyprogesterone, 21-deoxycortisol and 11-deoxycortisol were measured in 19 healthy dogs, 15 dogs with pituitary-dependent hypercortisolism (pdh) and eight dogs with other diseases before and one hour after an injection of synthetic adrenocorticotrophic hormone (acth). At both times the dogs with pdh had significantly higher concentrations of cortisol, 17alpha-hydroxypregnenolone, 17alpha-hydroxyprogesterone and 21-deoxycortisol than the healthy dogs. Basal 11-deoxycortisol concentrations were also significantly higher in dogs with pdh compared with healthy dogs. When compared with the dogs with other diseases, the dogs with pdh had significantly higher basal and post-acth cortisol and basal 21-deoxycortisol, and significantly lower post-acth 11-deoxycortisol concentrations. The dogs with other diseases had significantly higher post-acth cortisol, 17alpha-hydroxyprogesterone and 11-deoxycortisol concentrations than the healthy dogs. In general, the post-acth concentrations of 17alpha-hydroxypregnenolone, 17alpha-hydroxyprogesterone, 11-deoxycortisol and 21-deoxycortisol were more variable than the post-acth concentrations of cortisol, resulting in large overlaps of the concentrations of these hormones between the three groups. A two-graph receiver operating characteristic (ROC) analysis was used to maximise the sensitivity and specificity of each hormone for diagnosing hypercortisolism; it showed that the post-acth concentration of cortisol had the highest sensitivity and specificity. The overlaps between the healthy dogs, the dogs with pdh and the dogs with other diseases suggested that the individual precursor hormones would not be useful as a screening test for hypercortisolism.

Histological evaluation of the adrenal glands of seven dogs with hyperadrenocorticism treated with trilostane.

The lesions in the adrenal glands of seven dogs with hyperadrenocorticism that had been treated with trilostane were studied histologically. The glands of the six dogs with pituitary-dependent hyperadrenocorticism had moderate to severe cortical hyperplasia that was either diffuse or nodular. The lesions were more pronounced in the zona fasciculata than in the zona reticularis, and the zona glomerulosa was normal. In the dog with a functional adrenal tumour the non-tumour bearing adrenal gland showed mild nodular hyperplasia. Five of the seven dogs had variable degrees of adrenal necrosis, which was severe in two of them. The terminal deoxynucleotidyl transferase-mediated DUTP nick-end labelling (TUNEL) reaction specified areas of cell death as apoptosis in three of the dogs, and was positive in one of the dogs without visible areas of cell death. There were variable degrees of cortical haemorrhage in three of the dogs. In some of the dogs the lesions were severe enough to lead to hypoadrenocorticism.

Cortisol, aldosterone, cortisol precursor, androgen and endogenous ACTH concentrations in dogs with pituitary-dependant hyperadrenocorticism treated with trilostane.

Trilostane is thought to be a competitive inhibitor of the 3beta-hydroxysteroid dehydrogenase (3beta-HSD), an essential enzyme system for the synthesis of cortisol, aldosterone and androstenedione. Due to its reliable clinical efficacy, trilostane is increasingly used to treat dogs with pituitary-dependant hyperadrenocorticism (PDH). The objective of our study was to investigate the effect of trilostane on precursor concentrations located before (17alpha-OH-pregnenolone, dehydroepiandrostenedione) and after (17alpha-OH-progesterone, androstenedione, 11-deoxycortisol, 21-deoxycortisol) the proposed enzyme inhibition, on end products of steroid biosynthesis (cortisol and aldosterone) and on endogenous adrenocorticotrophic hormone (ACTH) concentrations in dogs with PDH. Hormones of the steroid biosynthesis pathway were evaluated in 15 dogs before and 1h after injection of synthetic ACTH prior to (t(0)), in weeks 1-2 (t(1)) and in weeks 3-7 (t(2)) of trilostane treatment. Endogenous ACTH concentrations were measured at the same time points before performing the ACTH stimulation test. During trilostane treatment baseline and post-stimulation cortisol concentrations decreased significantly. Baseline serum aldosterone levels showed a significant increase; post-stimulation values decreased. Baseline and post-stimulation 17alpha-OH-pregnenolone and dehydroepiandrostenedione concentrations increased significantly. 17alpha-OH-progesterone and androstenedione levels did not change. Post-stimulation 21-deoxycortisol concentrations decreased significantly, baseline 11-deoxycortisol concentrations increased significantly. Endogenous ACTH levels showed a significant increase. The significant increase in 17alpha-OH-pregnenolone and dehydroepiandrostenedione concentrations confirms an inhibitory effect of trilostane on the 3beta-HSD. Since 17alpha-OH-progesterone concentrations did not change, but cortisol concentrations markedly decreased, trilostane seems to influence additional enzymes of the hormone cascade, like the 11beta-hydroxylase and possibly the 11beta-hydroxysteroid dehydrogenase.

Efficacy of the repellent N,N-diethyl-3-methyl-benzamide (DEET) against tabanid flies on horses evaluated in a field test in Switzerland.

Female tabanid flies (Diptera: Tabanidae) can be a serious nuisance for horses because of their painful bites during blood feeding. They also play a primary role in mechanical transmission of a lentivirus causing Equine Infectious Anemia (EIA), a virus that has spread within Europe in recent years. According to the European law for products intended for use as a repellent on horses (recreational and sport horses), a field test is mandatory to demonstrate sufficient repellency of such a substance against the specific target fly species, but currently no agreed protocols are available for testing of potential repellents. The aim of the present study was to establish a protocol for a field test to investigate the efficacy of N,N-diethyl-3-methyl-benzamide (DEET, Brum®, Huebeli-Stud Horse Care AG) in a 15-17% oil-water emulsion against tabanid flies on horses up to four hours. Between July and August 2015, four horses on three farms each were tested on two consecutive days in a cross-over design. The four horses on Farm A were used in the pre-test as well as in the main test. Two and a half hours after repellent application the horses were lunged until sweating. Tabanid fly infestations were both photographed and directly counted during five minutes 3 and 4h after repellent application on the right side of the horses in the area from the head to the flank, belly and first third of the foreleg. Without repellent application, up to 29 tabanid flies were counted on a horse, whereas the maximum for the repellent treated horses was four. In 50% of the horses treated with DEET there were no Tabanids observed (efficacy 100%), and in all horses the tabanid fly counts were lower than in the control horses with one exemption at 4h. The efficacy of the DEET repellent was at least 80% and 71% respectively, three or four hours after application (with a confidence level of 89%). A fly trap (Horse Pal) revealed the presence of the tabanid species Tabanus brominus and Haematopota pluvialis, but also non-specified arthropods. The design of the present study simulated practical conditions, allowed to quantify the number of tabanids flies and to demonstrate repellency of DEET in horses.

Evaluation of clinical signs and causes of lower urinary tract disease in European cats.

OBJECTIVES: To investigate the clinical signs and causes of lower urinary tract disease (LUTD) in 77 cats. METHODS: Cats diagnosed with LUTD over a two-year period were included in the study. RESULTS: The study population comprised 67 male and 10 female cats. Uroliths occurred in 17 of the 77 cats (22 per cent), urethral plugs in eight cats (10 per cent) and urinary tract infection in six cats (8 per cent). In 44 cats (57 per cent), no specific cause for the disease was found and they were classified as having idiopathic LUTD. In two of the 77 cats (3 per cent) no definitive diagnosis was established. Pain was less common in cats with uroliths and haematuria was more often seen in cats with urinary tract infection. At presentation, urethral obstruction was diagnosed in 45 of the 77 cats (58 per cent). CLINICAL SIGNIFICANCE: The causes of LUTD found in cats in this study are similar to those that have been previously documented, and idiopathic LUTD is the most frequent diagnosis. However, the rate of urethral obstruction, particularly in cats with idiopathic LUTD, was higher than in other reports. The cause of this difference is unknown.

Auranofin versus placebo in the treatment of rheumatoid arthritis.

In a six-month, multicenter, double-blind study involving 340 patients, auranofin, 3 mg twice daily, was compared with placebo in the treatment of adult-onset rheumatoid arthritis. All patients were continued on a therapeutic regimen of salicylates and/or a newer nonsteroidal anti-inflammatory drug. Patients in both treatment groups who completed six months of therapy with coded medications showed significant improvement in the clinical features of rheumatoid arthritis (that is, number of tender and swollen joints, severity of pain, grip strength and duration of morning stiffness); however, the mean improvement was greater in the auranofin-treated group. Fifty-two percent of the auranofin-treated patients compared with 24 percent of the placebo-treated patients (p less than 0.05) were judged by their physician to have shown marked or moderate improvement. Only in the auranofin-treated patients was there significant improvement from baseline in the laboratory parameters of disease activity: erythrocyte sedimentation rate, IgA, IgG, and IgM. After at least three months of therapy, 30 percent (46 of 152) of the placebo-treated patients but only 9 percent (13 of 152) of the auranofin-treated patients (p less than 0.05) withdrew from coded medication due to insufficient therapeutic effect. Study medication was discontinued by 5 percent (eight of 152) of the auranofin-treated patients and 3 percent (four of 152) of the placebo-treated patients because of adverse therapy events (p = 0.24). This study demonstrates the efficacy of auranofin when added to salicylates and/or nonsteroidal anti-inflammatory drugs in the treatment of rheumatoid arthritis.

Synthesis and renal vasodilator activity of 2-chlorodopamine and N-substituted derivatives.

A four-step synthesis of 2-chlorodopamine (2b) is presented as well as methods for the syntheses of the N-methyl, ethyl, and n-propyl analogues (2c-e). Compounds 2b and 2c were essentially equipotent to dopamine for increasing renal blood flow in anesthetized dogs that had been treated with the alpha-adrenergic antagonist phenoxybenzamine. The increases in renal blood flow were blocked by the DA1 antagonist (R)-(+)-8-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepine. Compounds 2d and 2e were significantly less potent than dopamine in the same model; the increases in renal blood flow were attenuated by propranolol and blocked by a combination of propranolol and (R)-(+)-8-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepine. The significance of an o-chloro substituent on dopamine analogues for the activation of the DA1 receptor is briefly discussed.

Medical care use and expenditure among children and youth in the United States: analysis of a national probability sample.

Good access to health care for all US children and youth remains an important social policy goal. Recent patterns of access as reflected in the presence of regular care sources, health care use, health insurance coverage, and expenditures for medical care are described and analyzed using the subsample of all children 0 to 18 years of age from the 1980 National Medical Care Utilization and Expenditure Survey. Data from the survey indicate that in 1980, 92% of US children and youth had a regular care source and the same percentage were covered for the full year or part of the year by some form of public or private health insurance. However, use rates and patterns of expenditure continued to differ dramatically according to family background factors, particularly race, ethnicity, poverty status, and location of residence. These differences are analyzed and comparative data are presented for groups of children from various sociodemographic groups. Minority-group and near-poor children were found to be at highest risk for limited utilization of services and inadequate insurance coverage.

18F-fluorodeoxyglucose-positron emission tomography: a new explorative perspective.

18F-Fluorodeoxyglucose-positron emission tomography (18F-FDG-PET) is a new functional imaging technique available for clinical and experimental use. 18F-FDG-PET studies can be used for screening, localization and follow-up of hypermetabolic processes including malignancies, infections and autoimmune processes. For several years it has been applied in oncological, cardiological and neurological patients, but nowadays an increasing number of studies favours its use in patients with autoimmune diseases including large vessel arteritis. From the experimental view, this technique has even become more important since the introduction of a small PET scanner for the use in animal models. This review focuses on technical aspects, clinical experiences and experimental and future perspectives of 18F-FDG-PET, with a special emphasis on large vessel vasculitis and other autoimmune diseases.

Mobilization of peripheral blood progenitor cells for allogeneic transplantation: efficacy and toxicity of a high-dose rhG-CSF regimen.

Mobilization of PBPC was investigated in 19 healthy matched sibling donors using two different rhG-CSF regimens. Five donors (median age 39 years, range 17 to 57 years) received 10 micrograms rhG-CSF/kg bw once daily subcutaneously (s.c.), while 14 donors (median age 34 years, range 19 to 56 years) were treated with 10-12 micrograms rhG-CSF/kg bw twice daily s.c.. Leukapheresis was started on day 4 of rhG-CSF administration. Cytokine priming as well as collection of PBPCs were well tolerated. Application of twice daily rhG-CSF resulted in a higher yield of CD34+ cells in leukapheresis products than injection of once daily rhG-CSF. This high-dose twice daily rhG-CSF regimen is well tolerated and results in reliably high numbers of progenitor cells in the leukapheresis product in healthy donors, therefore collection as well as subsequent selection has been facilitated.

Surfactant protein B labelled with [(99m)Tc(CO)3(H20)3](+) retains biological activity in vitro..

UNLABELLED: Labelling of the hydrophobic surfactant protein B (SP-B) under non-reducing conditions was achieved with [(99m)Tc(CO)(3)(H2O)(3)](+) prepared according to Alberto et al. (JACS, 1998). The binding of radioactivity was protein-specific, with an overall radiochemical yield of 50%. Gel electrophoresis and Westernblot analyses showed no structural changes of SP-B. Spreading properties and surface activity of (99m)Tc-labelled SP-B in an air/water interface coincided with those of unlabelled SP-B. (99m)Tc-SP-B seems to be a promising agent to observe surfactant spreading under clinical conditions. BACKGROUND: Therapeutic results for surfactant instillation in clinical trials are conflicting. The (99m)Tc-labelling of surfactant would allow to observe its spreading in the lung under clinical conditions. METHODS: [(99m)Tc(CO)(3)(H2O)(3)](+) was prepared as described by Alberto et al. (JACS, 1998). This carbonyl complex was used for the direct labelling of surfactant protein B (SP-B) under non-reductive conditions by direct incubation with SP-B at elevated temperature followed by extraction into CHCl(3)/MeOH. RESULTS: The hydrophobic protein SP-B was labelled with [(99m)Tc(CO)(3)(H2O)(3)](+). An overall radiochemical yield of about 50% was achieved. HPLC-analysis revealed a single radiolabelled species according to UV elution profile of SP-B, supported by paper and size exclusion chromatography. Gel electrophoresis confirmed that the dimer structure of SP-B was preserved. Spreading properties of (99m)Tc-labelled SP-B in an air/water interface coincided with those of unlabelled SP-B. Spreading of radioactivity observed in a glass trough of 26 cm x 27 cm with a gamma camera was completed during the first 7-9 sec after application of (99m)Tc-labelled SP-B. The corresponding decrease of surface tension to 45 mN/m at the peripheral surface tension sensors took 7 sec +/- 2 sec (MEAN +/- STD; n = 3). CONCLUSIONS: Direct and specific (99m)Tc-labelling of the hydrophobic surfactant protein B was achieved using the [(99m)Tc(CO)(3)(H2O)(3)](+) precursor. This procedure can easily be used to prepare specifically labelled surfactant mixtures with spreading properties that coincide with those of unlabelled surfactant.