Formation of a full complement of cranial proprioceptors requires multiple neurotrophins

Inactivation of neurotrophin-3 (NT3) completely blocks the development of limb proprioceptive neurons and their end organs, the muscle spindles. We examined whether cranial proprioceptive neurons of the trigeminal mesencephalic nucleus (TMN) require NT3, brain-derived neurotrophic factor (BDNF) or neurotrophin-4 (NT4) for their development. Complements of TMN neurons and masticatory muscle spindles were decreased by 62% in NT3 null mutants, 33% in BDNF null mutants, and 10% in NT4 null mutant mice at birth. The extent of proprioceptive deficiencies differed among different masticatory muscles, particularly in NT3 null mice. Masticatory muscles of embryonic mice heterozygous for the NT3(lacZneo) or BDNF(lacZ) reporter genes expressed both NT3 and BDNF, consistent with target-derived neurotrophin support of TMN neurons. Although more than 90% of TMN neurons expressed TrkB as well as TrkC receptor proteins by immunocytochemistry in wild-type newborns, TrkC or TrkB null mice exhibited only partial proprioceptive deficiencies similar to those present in NT3 or BDNF;NT4 null mice. Thus, in terms of the survival outcome, two main subpopulations of TMN neurons may exist during embryogenesis, one dependent on TrkC/NT3 functioning and the other utilizing TrkB/BDNF signaling. The differential dependence of TMN neurons on neurotrophins may reflect differential accessibility of the neurons to limiting amounts of NT3, BDNF, or NT4 in target tissues, especially if the tissue distribution or levels of BDNF, NT3, and NT4 were dynamically regulated both spatially and temporally.

Inactivation of one copy of the mouse neurotrophin-3 gene induces cardiac sympathetic deficits

Whether two copies of the neurotrophin-3 (NT3) gene are necessary for proper development of cardiac sympathetic innervation was investigated in mice carrying a targeted inactivation of the NT3 gene. Heterozygous (+/-) and null (-/-) mutant mice had fewer stellate ganglion neurons than did wild-type (+/+) mice at postnatal day 0 (P0 or birth), and this deficit was maintained between adult (P60) +/- and +/+ mice. The sympathetic innervation of the heart matured postnatally in +/+ and +/- mice. Tyrosine hydroxylase (TH)-positive axons were restricted largely to the epicardium at P0, were concentrated around large blood vessels in the myocardium at P21, and were present among cardiac myocytes at P60. Cardiac norepinephrine (NE) concentrations paralleled the growth of the sympathetic axons into the heart. NE concentrations were equivalent among +/+, +/-, and -/- mice at birth, but differences between +/- and +/+ mice increased with age. Adult +/- mice also exhibited lower resting heart rates and sympathetic tonus than +/+ mice. Thus deletion of one copy of the NT3 gene translates into anatomical, biochemical, and functional deficits in cardiac sympathetic innervation of postnatal mice, thereby indicating a gene-dosage effect for the NT3 gene.

Comparison of the TOX A/B test to a cell culture cytotoxicity assay for the detection of Clostridium difficile in stools

The TOX A/B Test (Techlab, Blacksburg, VA, USA) was compared to cell culture cytotoxicity assay on 1109 consecutive diarrheal stool samples collected from patients with the presumptive diagnosis of Clostridium difficile disease. The TOX A/B Test is an enzyme immunoassay in a microtiter format that detects both toxins A and B. The procedure used for this study takes approximately 1.5 h to perform. Cell culture cytotoxicity was performed by using a fibroblast cell line in a microtiter format read at 4 h, 24 h, and 48 h. One hundred ninety-four of the 1109 samples were positive by the "gold standard" cytotoxicity assay, whereas 189 were positive by EIA. There was a 98.5% agreement between the two assays. When compared to the cytotoxicity assay, the EIA had an initial sensitivity of 94.3% and a specificity of 99.3%. However, after resolution of six discrepants using another ELISA for toxin A detection the sensitivity, specificity, positive and negative predictive values for the TOX A/B test are as follows: 94.5%; 100%; 100%; 98.8%. The corresponding values for the cytotoxicity assay are: 97%; 100%; 100%; and 99.3%. This test seems to have excellent sensitivity and specificity as compared to an in-house cell culture cytotoxicity assay. It is sensitive enough to use as a stand-alone test for the detection of C. difficile toxin in laboratories that do not have cell culture cytotoxicity testing capability.

Development of sensory neurons in the absence of NGF/TrkA signaling in vivo

The neurotrophin survival dependence of peripheral neurons in vitro is regulated by the proapoptotic BCL-2 homolog BAX. To study peripheral neuron development in the absence of neurotrophin signaling, we have generated mice that are double null for BAX and nerve growth factor (NGF), and BAX and the NGF receptor TrkA. All dorsal root ganglion (DRG) neurons that normally die in the absence of NGF/TrkA signaling survive if BAX is also eliminated. These neurons extend axons through the dorsal roots and collateral branches into the dorsal horn. In contrast, superficial cutaneous innervation is absent. Furthermore, rescued sensory neurons fail to express biochemical markers characteristic of the nociceptive phenotype. These findings establish that NGF/TrkA signaling regulates peripheral target field innervation and is required for the full phenotypic differentiation of sensory neurons.

Alterations in nigrostriatal dopaminergic function within BDNF mutant mice

The influence of brain-derived neurotrophic factor (BDNF) upon the nigrostriatal dopaminergic system was evaluated in weanling and adult mice carrying a targeted inactivated BDNF gene. Regional specificity of this BDNF mutation was assessed by assaying catecholamine concentrations within the corpus striatum, hypothalamus, and olfactory bulbs. In weanling mice dopamine, but not norepinephrine, concentrations within the corpus striatum of homozygous mutant (-/-) mice were significantly reduced with levels being 54% that of the wild-type controls (+/+) and 49% that of the heterozygous mutant (+/-) mice. While no differences were obtained among the three genotypes for hypothalamic dopamine, norepinephrine concentrations of -/- mice were significantly lower, being 62% of +/+ mice and 49% of +/- mice. The dopamine concentrations of -/- mice within the olfactory bulb were significantly reduced (69%) compared to the +/-, but not +/+ mice. Olfactory bulb norepinephrine concentrations showed a statistically significant difference among each of the three conditions with minimal levels in -/- mice (62% of +/+ and 45% of +/-). In the adults, catecholamine concentrations were measured only in +/+ and +/- mice since -/- mice do not typically survive past 21 days. Dopamine, but not norepinephrine, concentrations within the corpus striatum were significantly increased (116%) in +/- compared to +/+ mice. No other statistically significant differences were obtained in catecholamine concentrations within the hypothalamus or olfactory bulb in these adult mice. These results show that homozygous BDNF mutations produce severe depletions within the nigrostriatal dopaminergic system and substantial reductions of norepinephrine within the hypothalamus and olfactory bulb. Interestingly, maximal catecholamine concentrations for all areas sampled at both ages were observed in the +/- mice. These latter findings may indicate some subtle changes in catecholamine functions resulting from a heterozygous BDNF mutation.

[Liberation of drugs from impregnated wound dressings]

The present paper investigates drugs and polymers intended for the impregnation of textile carriers intended for use as wound covers. Their suitability was evaluated on the basis of the evaluation of the antimicrobial efficacy of a combination of trimetoprim and sulfadimidine with the local anaesthetics carbizocaine and lidocaine, and the immunomodulating substance fungal glucan. A greater inhibitory effect on the growth of microorganisms was shown by a combination of antimicrobial substances with carbizocaine. In the study of liberation of chlorohexidine from hydrophilic macromolecular dispersions its bond to glucan was confirmed. Dispersions of Natrosol proved to be more advantageous; chlorohexidine as well as local anaesthetics were released from them more rapidly than from methylcellulose gels. The dispersions under study are of a non-Newton character with pseudoplastic flow, glucan-containing gels are thixotropic.

Our standard method of reconstruction of the penis and urethra in female to male transsexuals

The authors used as a standard a one-stage method of microsurgical reconstruction of the penis, urethra and glans in 38 transsexual patients, a combination of Biemer's method, Trengove-Jones and Horton's suture of the glans. The reconstruction method is described in detail. Although reconstruction of the penis and urethra involved a group of 49 patients and accounted for less than 10% of all microsurgical tissue transfers in traumatology, oncological surgery and congenital defects, they are an important activity in systematic surgery.

A role for p75 receptor in neurotrophin-3 functioning during the development of limb proprioception

Neurotrophin-3 is indispensable for the development of limb proprioceptive neurons and their end organs, muscle spindles. To determine whether the low-affinity p75 receptor potentiates the actions of neurotrophin-3, we examined the development of the proprioceptive system in p75 null mutant mice that had either normal or decreased tissue levels of neurotrophin-3. Postnatal mice lacking both copies of the p75 gene had fewer sensory neurons in dorsal root ganglia, but normal complements of muscle spindles in fast hindlimb muscles, although the slow soleus muscle showed a 50% loss of spindles. However, compound mutants lacking both copies of the p75 gene as well as one copy of the neurotrophin-3 gene displayed a dystonic/ataxic phenotype similar to that observed previously in neurotrophin-3 null mutants devoid of proprioception. The compound mutants also exhibited a commensurate loss of parvalbumin-expressing (proprioceptive) neurons in dorsal root ganglia. The degree of deficiency of spindles (and presumably proprioceptive neurons) in the compound mutants exceeded the sum of deficits in single mutants lacking either both copies of p75 genes or one copy of neurotrophin-3 gene, suggesting a synergistic interaction between the p75 receptor and neurotrophin-3. Neuronal deficits in the compound mutants were present prior to embryonic day 14, indicating an early role for the p75 receptor in sensory neuronogenesis. Collectively, these data indicate that the p75 receptor is not essential for the survival and differentiation of most limb proprioceptive neurons when neurotrophin-3 is expressed at normal levels. However, the p75 receptor may act in synergy with neurotrophin-3 to enhance the survival of proprioceptive neurons when tissue levels of neurotrophin-3 are a limiting factor.

[Laparoscopic salpingectomy in heterotopic pregnancy after fertilization in vitro and embryo transfer]

A case report of a patient with tubal infertility treated by in vitro fertilisation and embryo transfer (IVF + ET) of 4 embryos is described. The patient presented with vaginal bleeding and lower abdominal pain and during emergency laparoscopy tubal heterotopic pregnancy was eliminated. The patient did well till term and delivered a 3450 g and 50 cm newborn with congenital valvular pulmonal artery stenosis. The incidence and treatment options of heterotopic pregnancies and influences of foetal outcome concerning congenital anomalies are discussed.

Why adult mammalian intrafusal and extrafusal fibers contain different myosin heavy-chain isoforms

Multiple isoforms of the contractile protein myosin are present in mammalian skeletal muscles. The diversity of the heavy-chain subunits of myosin (MyHCs) in intrafusal fibers is thought to reflect a pathway of differentiation that is unique to muscle spindles. In fact, intrafusal MyHCs are developmental isoforms expressed by the prenatal precursors of both intrafusal and extrafusal fibers. In adult limbs, developmental MyHCs persist in intrafusal, but not extrafusal fibers principally due to the afferent neurons that arrest their maturational replacement by MyHCs associated with faster shortening velocities. The slow shortening velocities that are characteristic of developmental MyHCs might be adaptive for precise calibration of muscle spindles as sense organs.

INAA and PIXE of atmospheric and combustion aerosols

Using instrumental neutron activation analyses and photon-induced x-ray emission techniques for analysis of size-fractionated atmospheric and combustion aerosols and other emission samples arising from fluidized-bed combustion of North Bohemian lignites up to 42 elements were determined in all samples types. This allowed the evaluation of element enrichment, time trends, and inter-element correlations and the performance of factor analysis of various fractions of atmospheric aerosols. The data obtained on mass and element size distributions of aerosols and emission samples obtained upon lignite combustion in an experimental scale atmospheric fluidized-bed combustor without and with added hydrated lime and limestone were used to elucidate the mechanism of abatement of toxic trace and matrix elements from flue gas.

Matrix effects in PIXE analysis of aerosols and ashes

A comparison of instrumental neutron activation analysis (INAA) and proton-induced X-ray emission (PIXE) results for size-fractionated atmospheric aerosols ("coarse" and "fine" fractions with an equivalent aerodynamic diameter of 2-10 microns and < 2 microns, respectively, or the PM10 fraction) showed that PIXE yielded significantly lower results for the PM10 and coarse fractions, especially for elements with a low Z resulting from a particle size effect. Somewhat lower PIXE results were also obtained for the fine fraction of atmospheric aerosols. A correction is also needed for irregularly shaped deposits of combustion aerosols collected by a cascade impactor in 11 size fractions ranging from 0.016 to 14.3 microns, as well as for thick samples of fly and bottom ashes. An equivalent layer thickness (ELT) model is proposed to correct the matrix effects in PIXE. The approaches for the calculation of ELT using a comparison of PIXE and INAA results or by comparing PIXE results obtained using two different incident proton beam energies (1.31 and 2.35 MeV) are described. The correction for the ash pellets and irregular deposits are also discussed.

Development of fusimotor innervation correlates with group Ia afferents but is independent of neurotrophin-3

Fusimotor neurons, group Ia afferents and muscle spindles are absent in mutant mice lacking the gene for neurotrophin-3 (NT3). To partition the effect of Ia afferent or spindle absence from that of NT3 deprivation on fusimotor neuron development, we examined the fusimotor system in a mutant mouse (NesPIXpNT3) that lacks Ia afferents and spindles, but has normal or elevated tissue levels of NT3 during embryogenesis. Fusimotor fibers were absent in lumbar ventral spinal roots, and limb muscles were devoid of Ia afferents and spindles in adult NesPIXpNT3 mice. In contrast, no deficiency in motoneuron numbers was observed in the trigeminal nucleus which contains cell bodies of motor axons innervating muscles of mastication. Spindles and Ia afferents were also present in the masticatory muscles. Thus, the development and/or survival of fusimotor neurons correlates with the presence of Ia afferents and/or spindles, and not with the amount of NT3 in the spinal cord or muscle.

Purification of carp (Cyprinus carpio) hepatopancreatic lactate dehydrogenase (EC 1.1.1.27)

Lactate dehydrogenase (LDH, EC 1.1.1.27) was isolated in 86% purity from carp (Cyprinus carpio) hepatopancreas using agarose T-gel (mercaptoethanol bound to agarose via divinylsulphone) affinity chromatography medium and Iontosorb phenyl hydrophobic chromatography medium. Gel filtration chromatography of the LDH obtained shows molecular weight to be 26,900 Da.

Microsurgical reconstruction during treatment of oncological diseases of head and neck

In 37 oncological patients where extensive resections of the face, maxilla, mandible or calva were necessary, microsurgical reconstructions were used in 27 cases as primary operations at the time of resection, and in 10 cases delayed or secondary operations were made. 49 flaps were used. In five cases two flaps were used in a single stage reconstruction, i.e. one flap for reconstruction of the mandible or buccal and on the other for facial side of the face. During operations a multidisciplinary approach of the surgical team comprising a maxillofacial surgeon, ENT and plastic surgeon is preferred.

Assessment of metals and metalloids in skin derivatives of volunteers from capital city of Prague, Czech Republic

Instrumental neutron activation was employed to determine 12 elements (Al, As, Co, Cr, Cu, Fe, Hg, Mn, Mo, Sb, V, Zn) in derivatives of the epidermis (human scalp hair, public hairs and toenails) from 188 women and 74 men of the population of the Capital City of Prague. Statistically significant differences are discussed, occurring during the comparison of groups arranged in terms of various factors (type of material analyzed, age, sex, environmental exposure of the dwelling and/or occupation locality, type of occupation--mental or manual, smoking, alcohol consumption, allergy, hysterectomy and selected diseases). Statistically significantly increased levels of elements in materials coming from Prague areas with higher environmental burden are considered as the most valuable result.

[Topical preparations for burns and their evaluation]

The study focused on some problems connected with the formulation of the topical preparation of the hydrocream type, intended for the treatment of dermal burns. Seven cream bases containing Emulgator E 2155, Polysorbate 80 and silicone oils were evaluated. The employed drugs included carbizocaine, lidocaine, chlorohexidine, and the immunomodulating substance glucan. A measurement of the surface tension of chlorohexidine and carbizocaine did not reveal interaction between these two drugs. Liberation tests confirmed a higher release of lidocaine in comparison with carbizocaine and chlorohexidine. The silicone oil present did not influence the release of carbizocaine, but it promoted the release of lidocaine and chlorohexidine. The determination of rheological parameters revealed that an addition of drugs influenced the flow properties of creams. The suitability of cream ointments was evaluated on the basis of their drying.

Neurotrophin-3 and trkC in muscle are non-essential for the development of mouse muscle spindles

Neurotrophin-3 (NT3) or TrkC null mutant mice were examined for the presence of muscle spindles. Muscles of mastication, but not limbs, contained spindles in newborn and adolescent mutants. The intramuscular distribution and morphological properties of spindles in mutant masticatory muscles were indistinguishable from those of wild-type spindles. Intrafusal fibers of NT3- or trkC-deficient spindles-expressed the slow-tonic isoform of myosin heavy chains, characteristic of wild-type spindles. Sensory nerve endings were observed in spindles of mutants by electron microscopy. Thus, NT3 or trkC, which is expressed in wild-type spindles, may serve functions other than those related to spindle assembly. Presumably, proprioceptive neurons innervating jaw muscles are dependent on factors other than NT3 for survival and maintenance.

Introduction of a neurotrophin-3 transgene into muscle selectively rescues proprioceptive neurons in mice lacking endogenous neurotrophin-3

To clarify the role of muscle-derived neurotrophin-3 (NT-3) in the development of sensory neurons, we generated transgenic mice selectively overexpressing NT-3 in skeletal muscles under the control of a myogenin promoter (myo-NT-3 mice). The myo-NT-3 transgene was then bred into an NT-3 null mutant (-/-) line to generate myo-NT-3, NT-3(-/-) mice in which NT-3 was expressed in muscles, but not elsewhere. Transient overexpression of NT-3 in developing muscles increased the number of proprioceptive neurons as well as the density of both their central and peripheral projections, resulting in more Ia afferents in spinal cord and more spindles (end organs of Ia afferents) in muscles. NT-3 expression restricted to muscles was sufficient to secure the development of proprioceptive neurons and their central and peripheral projections in myo-NT-3, NT-3(-/-) mice. The loss of nonproprioceptive neurons observed in NT-3(-/-) mice was not reversed by the transgene, suggesting that these neurons are regulated by NT-3 from sources other than muscle. We conclude that target-derived rather than intraganglionic NT-3 is preeminent in supporting the development of proprioceptive neurons. The level of NT-3 in developing muscles may be the principal factor determining the number of proprioceptive neurons in dorsal root ganglions and spindles in skeletal muscles of adults.

Limb proprioceptive deficits without neuronal loss in transgenic mice overexpressing neurotrophin-3 in the developing nervous system

The role of neurotrophin-3 (NT3) during sensory neuron development was investigated in transgenic mice overexpressing NT3 under the control of the promoter and enhancer regions of the nestin gene, an intermediate filament gene widely expressed in the developing nervous system. Most of these mice died during the first postnatal day, and all showed severe limb ataxia suggestive of limb proprioceptive dysfunction. Tracing and histological analyses revealed a complete loss of spindles in limb muscles, absence of peripheral and central Ia projections, and lack of cells immunoreactive to parvalbumin in the dorsal root ganglion (DRG). Despite these deficits, there was no neuronal loss in the DRG of these mice. At birth, transgenic DRG showed increased neuron numbers, and displayed a normal proportion of neurons expressing substance P, calcitonin gene-related peptide and the NT3 receptor trkC. Transgenic dorsal roots exhibited an increased number of axons at birth, indicating that all sensory neurons in transgenic mice projected to the dorsal spinal cord. Despite the absence of central Ia afferents reaching motorneurons, several sensory fibers were seen projecting towards ectopic high levels of NT3 in the midline of transgenic spinal cords. These findings suggest novel roles for NT3 in differentiation of proprioceptive neurons, target invasion and formation of Ia projections which are independent from its effects on neuronal survival.

Bilateral xanthine nephrolithiasis in a dog

Xanthinuria is an uncommon metabolic disorder clinically manifested as urolithiasis. There are two forms of the disease, congenital and iatrogenic. The former was diagnosed in a four-year-old dachshund bitch. The patient was presented with signs of terminal chronic renal failure. Urine was bacteriologically sterile with massive amorphous crystalluria. Bilateral nephrolithiasis was diagnosed at necropsy. The kidneys were shrunken with marked atrophy of the renal cortex and medulla. Infrared spectrometry revealed that the stones comprised 100 per cent xanthine. Later, two of the patient's siblings were examined for urine xanthine content; both showed higher concentrations of xanthine than a control dog. The described case is compared with seven known published cases of congenital xanthinuria.

Brown recluse spider bite: a case study

The case of a young man with a chronic, resistant, and unpredictable wound is described. The wound is believed to have been caused by the bite of a brown recluse spider. This article presents a brief overview of the potential sequelae of brown recluse spider bite and a pictorial review of this young man's wound during a 22-month period.

Environmental specimen banking in the Czech Republic: a pilot study

In recognition of the importance of environmental specimen banking (ESB) as an important component of the described ongoing real-time environmental and health-related monitoring programmes, a proposal for a planned ESB pilot study in the Czech Republic is presented. Selection of biomonitors, analytes, sampling techniques and sites is discussed, especially with regard to the possible harmonization with ESB already operational abroad. Availability of validated analytical techniques for determination of up to 30 elements using nuclear and spectroscopic techniques, including speciation of several metals, and of the most important organic pollutants employing various chromatographic techniques in biological and environmental samples is demonstrated.

[Transdermal administration of drugs. XI. Formulation of polymeric matrices with metoprolol in transdermal therapeutic systems]

The paper is concerned with formulation studies of the transdermal therapeutic system of the matrix type with beta-adrenolytic drug metoprolol. The base of the hydrophobic matrix is the biocompatible polymer-silicone rubber, and the hydrophilic matrix was prepared from the polyacrylate polymer of the Eudragit type. The properties of the silicone matrix were modified by the additive Methocel F 4M, macrogol 600, copolymer p (HEMA) with methacrylic acid and polyacrylamide. The matrices were evaluated on the basis of the results of in vitro liberation of the drug at 32 degrees C. The liberation profiles of metoprolol were evaluated by means of the parameters of Tornquist hyperbolic function calculated by nonlinear regression. Of the composite ingredients of the silicone matrix, Methocel F 4M proved to be the best. Metoprolol was released most from the hydrophilic matrix prepared from Eudragit NE 30D. It released 12.32 mg.cm(-2).24 h-1 of metoprolol.