A two-circuit strategy for intraoperative extracorporeal support during single lung transplantation in a patient bridged with venovenous extracorporeal membrane oxygenation

Venovenous extracorporeal membrane oxygenation is increasingly used as a bridging strategy in decompensating patients awaiting lung transplantation. Various approaches for continuing support intraoperatively have been previously described. A two-circuit strategy that uses the in situ venovenous extracorporeal membrane oxygenation circuit supplemented with peripheral cardiopulmonary bypass allows for diversion of native cardiac output away from the transplanted lung as well as seamless continuation of venovenous extracorporeal membrane oxygenation postoperatively.

Binary Colloidal Nanoparticle Concentration Gradients in a Centrifugal Field at High Concentration

Binary colloidal nanoparticles have been found to form different types of crystalline phases at varied radial positions in a centrifugal field by Chen et al. ( ACS Nano 2015, 9, 6944-50). The variety of binary phase behaviors resulted from the two different nanoparticle concentration gradients, but to date, the gradients can only be empirically controlled. For the first time, we are able to measure, fit, and simulate binary hard-sphere colloidal nanoparticle concentration gradients at high particle concentrations up to 30 vol %, which enables tailor-made gradients in a centrifugal field. By this means, a continuous range of binary particle concentration ratios can be accessed in one single experiment to obtain an extended phase diagram. By dispersing two differently sized silica nanoparticles labeled with two different fluorescence dyes in a refractive index matching solvent, we can use a multi-wavelength analytical ultracentrifuge (MWL-AUC) to measure the individual concentration gradient for each particle size in sedimentation-diffusion equilibrium. The influence of the remaining slight turbidity at high concentration can be corrected using the MWL spectra from the AUC data. We also show that the experimental concentration gradients can be fitted using a noninteracting nonideal sedimentation model. By using these fitted parameters, we are able to simulate nanoparticle concentration gradients, which agreed with the subsequent experiments at a high concentration of 10 vol % and thus allowed for the simulation of binary concentration gradients of hard-sphere nanoparticles in preparative ultracentrifuges (PUCs). Finally we demonstrated that by simulating the concentration gradients in PUCs, a continuous and extended binary nanoparticle phase diagram can be obtained by simply studying the structure evolution along the centrifugal field for one single sample instead of a large number of experiments with discrete compositions as in conventional studies.

Suppression of tumor-derived Semaphorin 7A and genetic ablation of host-derived Semaphorin 7A impairs tumor progression in a murine model of advanced breast carcinoma

Solid tumors can generate a plethora of neurogenesis-related molecules that enhance their growth and metastasis. Among them, we have identified axonal guidance molecule Semaphorin 7A (SEMA7A) in breast cancer. The goal of this study was to determine the therapeutic effect of suppressing SEMA7A levels in the 4T1 murine model of advanced breast carcinoma. We used anti-SEMA7A short hairpin RNA (shRNA) to gene silence SEMA7A in 4T1 mammary tumor cells. When implanted into the mammary fat pads of syngeneic mice, SEMA7A shRNA-expressing 4T1 tumors exhibited decreased growth rates, deferred metastasis and reduced mortality. In vitro, SEMA7A shRNA-expressing 4T1 cells had weakened proliferative, migratory and invasive abilities, and decreased levels of mesenchymal factors. Atomic force microscopy studies showed that SEMA7A shRNA-expressing 4T1 cells had an increase in cell stiffness that corresponded with their decreased malignant potential. Genetic ablation of host-derived SEMA7A further enhanced the antitumor effects of SEMA7A shRNA gene silencing in 4T1 cells. Our preclinical findings demonstrate a critical role for SEMA7A in mediating mammary tumor progression.

Sexuality, Self-Esteem and Partnership Quality in Infertile Women and Men

Introduction: Infertile couples often report quality-of-life impairments, especially in terms of sexuality, self-esteem and partnership quality. So far, there have been no systematic studies of the sex lives and behaviour of infertile women and men before and after the emergence of their mutual desire for a child. Materials and Methods: From February 2010 to August 2010 all couples starting treatment either at Heidelberg University's Women's Hospital or at the Fertility Center Berlin were asked to fill out the Self-Esteem and Relationship Questionnaire (SEAR). A total of n = 158 women and n = 153 men participated in the study. Results: Decreasing tendencies were observable for both partners in the domains Sexual Relationship Satisfaction and Confidence and in the subscales Self-Esteem and Overall Relationship Satisfaction. There were especially clear indications of a loss of spontaneous sexuality during the experience of infertility. We were also able to establish that infertility has a negative impact on women's self-esteem. Discussion: The results of this study indicate that SEAR can be used as a feasible instrument for identifying infertile women and men whose infertility has a negative effect on their relationship quality and/or sex lives.

Microbially-produced peptides having potential application to the prevention of dental caries

Strategies advanced to decrease the occurrence of dental caries have in the past typically focussed upon attempting to reduce plaque accumulation by application of broad-spectrum antibacterial agents. In recent years however there has been growing interest in the application of a more targeted approach to the selective elimination from plaque of those bacterial species that are specifically implicated as the aetiological agents of this disease. This review focuses upon a number of the small bacterially-produced peptide antibiotics known as bacteriocins that are currently being explored for their potential role in the treatment and prevention of dental caries.

Genetic heterogeneity in rapid onset dystonia-parkinsonism: description of a new family

Rapid onset dystonia-parkinsonism (RDP) is a rare movement disorder with autosomal dominant inheritance, characterised by sudden onset of dystonic spasms and slowness of movement. To date, three families have been described that share linkage to the same location on chromosome 19q13, designated DYT12. Very recently, mutations in the ATP1A3 gene at the DYT12 locus have been demonstrated in seven unrelated patients, including the three previously linked families. A large RDP family is reported here, with eight definitely and one possibly affected members, that is not linked to the DYT12 region and has no mutation in the ATP1A3 gene. Predominant cranial-cervical involvement of dystonia occurred in this family, which has also been described in patients with idiopathic torsion dystonia linked to the DYT6 region on chromosome 8 and is a rare finding in DYT1 dystonia. Molecular genetic analysis also excluded linkage to the DYT6 locus and the GAG deletion in DYT1, suggesting at least one additional RDP gene.

Transverse structure of nucleon parton distributions from lattice QCD

This work presents the first calculation in lattice QCD of three moments of spin-averaged and spin-polarized generalized parton distributions in the proton. It is shown that the slope of the associated generalized form factors decreases significantly as the moment increases, indicating that the transverse size of the light-cone quark distribution decreases as the momentum fraction of the struck parton increases.

Combined standard graft-versus-host disease (GvHD) prophylaxis with mycophenolate mofetil (MMF) in allogeneic peripheral blood stem cell transplantation from unrelated donors

In this open single-centre phase II study, MMF was added on day +10 after allogeneic transplantation to standard immunosuppressive prophylaxis consisting of cyclosporine and methotrexate to decrease the incidence of GvHD. In all, 30 patients aged 20-59 years with advanced haematological malignancies received an unmanipulated blood-stem-cell graft (median of 8.5 x 10(6) CD34(+) and 349 x 10(6) CD3(+) cells per bodyweight) from matched unrelated (n=26), or mismatched donors (n=4). Prior to transplantation, 13 patients underwent fractionated total body irradiation and cyclophosphamide, one patient additional etoposide. In all, 16 patients received reduced conditioning of fludarabin, busulfan, and antithymocyte globulin. All patients engrafted in a median of 12 days, and 19 developed acute GvHD>/=II, including two patients with GvHD III and three with GvHD IV. Subsequently, nine patients developed limited and two patients extensive chronic GvHD. With a median follow-up of 28 months, the overall survival is 53.3% and disease-free survival 50%, respectively. Only two deaths were due to GvHD IV. Out of 13 patients, 10 being CMV IgG positive became positive for pp65. In conclusion, this MMF schedule seems to be safe and feasible in the prophylaxis of severe acute GvHD for high-risk patients, restricted by an increased risk for reactivating CMV in seropositive patients.

Spatiotemporal transcription of connexin45 during brain development results in neuronal expression in adult mice

Characterization of the expression pattern of connexins in neural tissue is a necessary prerequisite for understanding the functional relevance of the corresponding gap junction channels in brain. Here we describe the cell type-specific expression of connexin45 in the CNS and the spatiotemporal expression pattern from embryonic day 19.5 to adult brain using a recently described connexin45 LacZ-reporter mouse. The connexin45 gene is highly expressed during embryogenesis and up to 2 weeks after birth in nearly all brain regions. Afterward its expression is restricted to the thalamus, the CA3 region of hippocampus and the cerebellum. In adult mouse brain, the pattern of LacZ-staining in combination with the analysis of different neuronal and glial marker proteins strongly suggests that connexin45 is expressed in neurons, but presumably not in astrocytes or mature oligodendrocytes. Expression of the LacZ/connexin45 reporter gene in subsets of neurons, such as cerebral cortical, hippocampal and thalamic neurons as well as basket and stellate cells of cerebellum should be corroborated by functional investigations of connexin45 protein in electrical synapses. Based on its expression pattern during development, we suggest that the connexin45-containing gap junction channels have a rather ubiquitous role during brain development and may contribute to functional specification in certain subsets of neurons in the adult brain.

Hereditary myoclonus-dystonia associated with epilepsy

A five-generation Dutch family with inherited myoclonus-dystonia (M-D) is described. Genetic analysis revealed a novel truncating mutation within the epsilon-sarcoglycan gene (SGCE). In three of five gene carriers, epilepsy and/or EEG abnormalities were associated with the symptoms of myoclonus and dystonia. The genetic and clinical heterogeneity of M-D is extended. EEG changes and epilepsy should not be considered exclusion criteria for the clinical diagnosis of M-D.

Morphological development and neurochemical differentiation of cerebellar inhibitory interneurons in microexplant cultures

The cerebellar cortex comprises a rather limited variety of interneurons, prominently among them inhibitory basket and stellate cells and Golgi neurons. To identify mechanisms subserving the positioning, morphogenesis, and neurochemical maturation of these inhibitory interneurons, we analyzed their development in primary microexplant cultures of the early postnatal cerebellar cortex. These provide a well-defined, patterned lattice within which the development of individual cells is readily accessible to experimental manipulation and observation. Pax-2-positive precursors of inhibitory interneurons were found to effectively segregate from granule cell perikarya. They emigrate from the core explant and avoid the vicinity of granule cells, which also emigrate and aggregate into small clusters around the explant proper. This contrasts with the behavior of Purkinje neurons, which remain within the explant proper. During migration, a subset of Pax-2-positive cells gradually acquires a GABAergic phenotype, and subsequently also expresses the type 2 metabotropic receptor for glutamate, or parvalbumin, markers for Golgi neurons and basket or stellate cells, respectively. The latter eventually orient their dendrites such that they take a preferentially perpendicular orientation relative to granule cell axons. Both the neurochemical maturation of basket/stellate cells and the specific orientation of their dendrites are independent of their continuous contact with radially oriented glia or Purkinje cell dendrites projecting from the core explant. Numbers of parvalbumin-positive basket/stellate cells and the prevalence of glutamate-positive neurites, which form a dense network preferentially within cell clusters containing granule cell perikarya and their dendrites, are subject to regulation by chronic depolarization. In contrast, brain-derived neurotrophic factor results in a drastic decrease of numbers of basket/stellate cells. These findings document that granule cell axons (parallel fibers) are the major determinant of basket/stellate cell dendritic orientation. They also show that the neurochemical maturation of cerebellar interneurons is sensitive to regulation by activity and neurotrophic factors.

Phenotypic features of myoclonus-dystonia in three kindreds

BACKGROUND

Myoclonus-dystonia (M-D) is a movement disorder with involuntary jerks and dystonic contractions. Autosomal dominant alcohol-responsive M-D is associated with mutations in the epsilon-sarcoglycan gene (SGCE) (six families) and with a missense change in the D2 dopamine receptor (DRD2)gene (one family).

OBJECTIVE

To investigate the clinical phenotype associated with M-D including motor symptoms, psychiatric disorders, and neuropsychological deficits.

METHODS

Fifty individuals in three M-D families were evaluated and a standardized neurologic examination and DNA analysis were performed. Psychiatric profiles were established with the Diagnostic Interviews for Genetic Studies (DIGS) and the Yale-Brown Obsessive-Compulsive Scale (YBOCS). Cognition was evaluated with standardized neuropsychological tests.

RESULTS

Distinct truncating mutations in the SGCE gene were identified in each family. Additionally, a missense alteration in the DRD2 gene was previously found in one family. Motor expression was variable, with onset of myoclonus or dystonia or both affecting the upper body and progression to myoclonus and dystonia in most cases. Psychiatric profiles revealed depression, obsessive-compulsive disorder, substance abuse, anxiety/panic/phobic disorders, and psychosis in two families, and depression only in the third family. Averaged scores from cognitive testing showed impaired verbal learning and memory in one family, impaired memory in the second family, and no cognitive deficits in the third family.

CONCLUSIONS

Cognitive deficits may be associated with M-D. Psychiatric abnormalities correlate with the motor symptoms in affected individuals. Assessment of additional M-D families with known mutations is needed to determine whether these are characteristic phenotypic manifestations of M-D.

Hepatic veno-occlusive disease (VOD) with complete occlusion of liver venules after tandem autologous stem cell transplantation-- successful treatment with high-dose methylprednisolone and defibrotide

Veno-occlusive disease (VOD) is a life-threatening complication following allogeneic or autologous stem cell transplantation. We report on a patient with a high grade B-cell lymphoma who presented 28 days after the second autologous stem cell transplantation with weight gain, ascites, hyperbilirubinemia, and liver venules occlusion as demonstrated by sonography. Starting with high-dose methylprednisolone treatment followed by defibrotide maintenance therapy the patient showed dramatic complete response of VOD, resulting in a normal sonography of the liver and normalization of laboratory values. The response of the occlusion of nearly all liver venules underlines the value of anti-inflammatory treatment combined with new thrombolytic medication such as defibrotide for the treatment of severe VOD.

Myoclonus dystonia: possible association with obsessive-compulsive disorder and alcohol dependence

BACKGROUND

Inherited myoclonus-dystonia (M-D) is a disorder that is characterized primarily by myoclonic jerks and is often accompanied by dystonia. In addition to motor features, psychiatric disease is reported in some families.

METHODS

To determine whether the same genetic etiology underlies both neurologic and psychiatric signs, the authors studied psychiatric symptoms in nonmanifesting carriers (NMC), noncarriers (NC), and manifesting carriers (MC) in three families demonstrating linkage of M-D to the 7q21 locus. Interviewers administered the computerized version of the Composite International Diagnostic Interview. Algorithms for the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnosis of obsessive-compulsive disorder (OCD), generalized anxiety disorder, major affective disorder, alcohol abuse, alcohol dependence, drug abuse, and drug dependence were used. Rates of disorders among the MC, NMC, and NC were compared.

RESULTS

Of 55 participating individuals, 16 were MC, 11 were NMC, and 28 were NC. The rate of OCD was greater in carriers (5/27) compared with NC (0/28) (p = 0.023). It was also greater in the symptomatic gene carriers (4/16) compared with the asymptomatic group (1/11) (p = 0.022). Alcohol dependence was increased in the symptomatic carriers (7/16) (p = 0.027), but not in the carrier group overall (7/27).

CONCLUSION

OCD may be associated with the DYT11 M-D gene; however, a larger sample is necessary to confirm this finding. Alcohol dependence is highly associated with expressing symptoms of M-D. This may be explained by self-medication with alcohol to improve motor symptoms of M-D.

Modulation of human T cell responses and macrophage functions by onchocystatin, a secreted protein of the filarial nematode Onchocerca volvulus

Immune responses of individuals infected with filarial nematodes are characterized by a marked cellular hyporesponsiveness and a shift of the cytokine balance toward a Th2/Th3 response. This modulation of cellular immune responses is considered as an important mechanism to avoid inflammatory immune responses that could eliminate the parasites. We investigated the immunomodulatory potential of a secreted cysteine protease inhibitor (onchocystatin) of the human pathogenic filaria Onchocerca volvulus. Recombinant onchocystatin (rOv17), a biologically active cysteine protease inhibitor that inhibited among others the human cysteine proteases cathepsins L and S, suppressed the polyclonally stimulated and the Ag-driven proliferation of human PBMC. Stimulated as well as unstimulated PBMC in the presence of rOv17 produced significantly more IL-10, which was paralleled in some situations by a decrease of IL-12p40 and preceded by an increase of TNF-alpha. At the same time, rOv17 reduced the expression of HLA-DR proteins and of the costimulatory molecule CD86 on human monocytes. Neutralization of IL-10 by specific Abs restored the expression of HLA-DR and CD86, whereas the proliferative block remained unaffected. Depletion of monocytes from the PBMC reversed the rOv17-induced cellular hyporeactivity, indicating monocytes to be the target cells of immunomodulation. Therefore, onchocystatin has the potential to contribute to a state of cellular hyporesponsiveness and is a possible pathogenicity factor essential for the persistence of O. volvulus within its human host.

Novel lamin A/C mutations in two families with dilated cardiomyopathy and conduction system disease

BACKGROUND

The LMNA gene, one of 6 autosomal disease genes implicated in familial dilated cardiomyopathy, encodes lamins A and C, alternatively spliced nuclear envelope proteins. Mutations in lamin A/C cause 4 diseases: Emery-Dreifuss muscular dystrophy, limb girdle muscular dystrophy type 1B, Dunnigan-type familial partial lipodystrophy, and dilated cardiomyopathy.

METHODS AND RESULTS

Two 4-generation white families with autosomal dominant familial dilated cardiomyopathy and conduction system disease were found to have novel mutations in the rod segment of lamin A/C. In family A a missense mutation (nucleotide G607A, amino acid E203K) was identified in 14 adult subjects; disease was manifest as progressive conduction disease in the fourth and fifth decades. Death was caused by heart failure. In family B a nonsense mutation (nucleotide C673T, amino acid R225X) was identified in 10 adult subjects; disease was also manifest as progressive conduction disease but with earlier onset (third and fourth decades), ventricular dysrhythmias, left ventricular enlargement, and systolic dysfunction. Death was caused by heart failure and sudden cardiac death. Skeletal muscle disease was not observed in either family.

CONCLUSIONS

Novel rod segment mutations in lamin A/C cause variable conduction system disease and dilated cardiomyopathy without skeletal myopathy.

Developmental expression of heterotrimeric G-proteins in the murine cerebellar cortex

We utilized the murine cerebellum to analyze the expression of G-proteins during vertebrate neural differentiation. Combining reverse transcription-polymerase chain reaction and immunocytochemistry, we monitored the expression and cellular localization, within the nascent cerebellar cortex, of G-proteins subunits known to mediate signal transduction in the adult cerebellum. The mRNAs encoding subunits Galphaq, Galphao, Galphai-2, and Galphaz are expressed in the cerebellar anlage at least from embryonic day 14 onward, and relative levels of these mRNAs do not change appreciably from E14 to adulthood. Galphao, Galphaz, and Galphai-2 could be localized to granule cell neuroblasts and postmigratory, mature granule cells, but not to early postmitotic, premigratory, and migrating granule neurons. All of the Galpha subunits analyzed could also be localized to the cell somata of postmitotic Purkinje neurons, irrespective of age. In contrast, Purkinje cell dendrites stained for Galphao only up to postnatal day 8, dendritic immunoreactivity for Galphaz increased during dendritogenesis, and appreciable levels of Galphai-2 and Galphaq were seen in Purkinje cell dendrites only transiently during the 2nd and 3rd postnatal week. Of the G-beta and -gamma subunits analyzed (beta1, beta2, gamma2, gamma3, gamma5, and gamma7), only expression of gamma3 varied with development. It could be localized to Purkinje cell somata and dendrites in early postnatal, but not in adult animals. These changes in the cellular distribution and subcellular segregation of G-proteins are correlated to tangible aspects of cerebellar cortical histogenesis and suggest a role for G-protein-mediated signaling in their mechanistic implementation.

Folding incompetence of cathepsin L-like cysteine proteases may be compensated by the highly conserved, domain-building N-terminal extension of the proregion

Folding of cathepsins L and S depend upon their proregion which extends the enzyme part by about 100 amino acids. Only a minority of the prosequence follows the structural template provided by the enzyme part; the majority forms an autonomous minidomain fairly distant from the active site cleft. We suggest that this prodomain may be the structural correlate of a foldase function of the proregion within the cathepsin L-like subfamily of papain-type cysteine proteases and report on a functional approach supporting this hypothesis.

Functional expression of the new gap junction gene connexin47 transcribed in mouse brain and spinal cord neurons

A new mouse gap junction gene that codes for a protein of 46,551 Da has been identified and designated connexin47 (Cx47). It mapped as a single-copy gene to mouse chromosome 11. In human HeLa cells and Xenopus oocytes, expression of mouse Cx47 or a fusion protein of Cx47 and enhanced green fluorescent protein induced intercellular channels that displayed strong sensitivity to transjunctional voltage. Tracer injections in Cx47-transfected HeLa cells revealed intercellular diffusion of neurobiotin, Lucifer yellow, and 4',6-diamidino-2-phenylindole. Recordings of single channels yielded a unitary conductance of 55 pS main state and 8 pS substate. Cx47 mRNA expression was high in spinal cord and brain but was not found in retina, liver, heart, and lung. A low level of Cx47 expression was detected in ovaries. In situ hybridizations demonstrated high expression in alpha motor neurons of the spinal cord, pyramidal cells of the cortex and hippocampus, granular and molecular layers of the dentate gyrus, and Purkinje cells of the cerebellum as well as several nuclei of the brainstem. This expression pattern is distinct from, although partially overlapping with, that of the neuronally expressed connexin36 gene. Thus, electrical synapses in adult mammalian brain are likely to consist of different connexin proteins depending on the neuronal subtype.

Brain-derived neurotrophic factor modulates dendritic morphology of cerebellar basket and stellate cells: an in vitro study

The dendrites of cerebellar basket/stellate cells show a highly stereotyped orientation relative to granule cell axons (parallel fibers) and Purkinje cell dendrites. This specific morphology is acquired during the early postnatal phase of cerebellar development, when basket/stellate cells become synaptically integrated with Purkinje neurons and granule cells. In the present study, we used primary cerebellar cultures to test how the spatial arrangement of granule cell axons affects basket/stellate cell dendritic morphology. In addition, we sought to determine whether active signals as might be provided by granule cells, i.e. synaptic input and the neurotrophin, brain-derived neurotrophic factor, affect basket/stellate cell development. Our results confirm the critical role of parallel fiber orientation for basket/stellate dendritic morphogenesis. Moreover, we found that both electrical activity and brain-derived neurotrophic factor increased basket and stellate cell dendritic arborization. Together with previously published findings, our data led to the conclusion that both structural cues and active interneuronal signaling collaborate to bring about the precise morphogenesis of cerebellar basket/stellate cells. The distinct responses of various cerebellar phenotypes towards the morphogenetic effects of brain-derived neurotrophic factor suggest that this neurotrophin, within the developing cerebellum, enhances synaptic connectivity by concerting the formation of appropriate pre- and postsynaptic structures.

Glycosylphosphatidylinositol-specific phospholipase D of human serum--activity modulation by naturally occurring amphiphiles

The enzymatic properties of glycosylphosphatidylinositol-specific phospholipase D (EC 3.1.4.50) were characterized using a 6,000-fold purified enzyme. This was obtained in 100 microg amounts from human serum with a recovery of 35%. Pure alkaline phosphatase containing one anchor moiety per molecule was used as substrate. The enzyme is stimulated by n-butanol, but in contrast to other phospholipases this activation is not produced by a transphosphatidylation reaction. The previously reported non-linearity of the specific activity with respect to phospholipase concentration in the test was no longer observed upon purification, indicating inhibitor removal. The serum inhibitor(s) co-chromatograph with serum proteins and lipoproteins. The main part of the inhibitory activity was found in the lipid fraction after protein denaturation and can be subfractionated into acid phospholipids, cholesteryl esters and triacylglycerides. Added phosphatidyl-serine, phosphatidylinositol, phosphatidylglycerol, gangliosides, cholesteryl esters, and sphingomyelins turned out to be strong inhibitors, as well as phosphatidic acid. Phosphatidylethanolamine and various monoacylglycerols were found to be activators. The low glycosylphosphatidylinositol-specific phospholipase activity found in native serum did not increase significantly upon 90% removal of phospholipids by n-butanol. High serum concentrations of strongly inhibiting compounds, complex kinetic interactions among aggregates of these substances, and compartmentalization effects are discussed as possible reasons for the observed inactivity.

An evolutionarily conserved tripartite tryptophan motif stabilizes the prodomains of cathepsin L-like cysteine proteases

Cathepsin L-like cysteine proteinases contain an evolutionarily highly conserved alpha-helical motif in the proregion. This is called the ER(F/W)N(I/V)N motif according to the conserved amino acids along one side of the helix. We studied the function of this motif using site-directed mutagenesis experiments of human procathepsin S. We replaced each of these amino acids with alanine and constructed deletion mutants lacking parts of the helix. All mutants were expressed in HEK 293 cells, but only one, W52A, was not processed to mature cathepsin S, nor was it phosphorylated or secreted into the culture medium. W52 is part of the hydrophobic core in the propeptide region of cathepsin S comprising two additional tryptophan residues, W28 and W31, also conserved among cathepsin L-like cysteine peptidases. Replacement of the latter with alanine led to consequences similar to those with the W52A mutation. Recombinant propeptides containing mutations of one of the three tryptophan residues were three orders of magnitude less effective as inhibitors of mature cathepsin S than the wild-type propeptide. The results point to a dominant role of the respective hydrophobic stack in the proper folding, transport and maturation of procathepsin S and related cathepsin L-like cysteine proteinases.

Spatial and temporal changes in natural and target deprivation-induced cell death in the mouse inferior olive

The survival of inferior olive neurons is dependent on contact with cerebellar Purkinje cells. There is evidence that this dependence changes with time. Because inferior olivary axons, called climbing fibers, already show significant topographical ordering in cerebellar target zones during late embryogenesis in mice, the question arises as to whether olive neurons are dependent on target Purkinje cells for their survival at this early age. To better characterize this issue, inferior olive development was studied in two transgenic mouse mutants, wnt-1 and L7ADT, with embryonic and early postnatal loss of cerebellar target cells, respectively, and compared to that in the well-studied mutant, Lurcher. Morphological criteria as well as quantitative measures of apoptosis were considered in this developmental analysis. Survival of inferior olive neurons is observed to be independent of Purkinje cells throughout embryogenesis, but dependence begins immediately at birth in both wild types and mutants. Thereafter, wild types and mutants show a rapid increase in olive cell apoptosis, with a peak at postnatal day 4, followed by a period of low-level, but significant, apoptosis that continues to at least postnatal day 11; the main difference is that apoptosis is quantitatively enhanced in the mutants compared to wild types. The multiphasic course of these effects roughly parallels the known phases of climbing fiber synaptogenesis. In addition, despite significant temporal differences among the mutants with respect to absolute numbers of dying cells, there are common spatial features suggestive of distinct intrinsic programs linking different olivary subnuclei to their targets.

The alpha1/2 helical backbone of the prodomains defines the intrinsic inhibitory specificity in the cathepsin L-like cysteine protease subfamily

Proregions of papain-like cysteine proteases are potent and often highly selective inhibitors of their parental enzymes. The molecular basis of their selectivity is poorly understood. For two closely related members of the cathepsin L-like subfamily we established strong selectivity differences. The propeptide of cathepsin S was observed to inhibit cathepsin L with a K(i) of 0.08 nM, yet cathepsin L propeptide inhibited cathepsin S only poorly. To identify the respective structural correlates we engineered chimeric propeptides and compared their inhibitory specificity with the wild-types. Specificity resided in the N-terminal part, strongly suggesting that the backbone of the prodomain was the underlying structure.

Changing subcellular distribution and activity-dependent utilization of a dendritically localized mRNA in developing Purkinje cells

In cerebellar Purkinje neurons, the degree of dendritic segregation of the Purkinje cell-specific mRNA L7/pcp-2 is correlated with their development and synaptic investment. This developmental pattern is also observed in Purkinje cells in primary dissociated culture. Short-term (12-48 h) stimulation of cultured Purkinje cells by potassium-induced depolarization or blockade of their inhibitory GABAergic input results in an increased incidence of Purkinje cells with L7/pcp-2 mRNA-positive dendrites and increased levels of L7 protein expression, the latter by a posttranscriptional mechanism. None of these treatments affected the localization of the mRNA encoding calbindin D28k nor the level of this protein in Purkinje neurons. Protracted exposure to depolarizing levels of potassium or elimination of GABAergic transmission resulted in conspicuous changes of Purkinje cell dendritic morphology. These data suggest a scenario in which activity-driven translation of subcellularly segregated mRNAs may contribute to the developmental and functional plasticity of nerve cells.

Elastin gene deletions in Williams syndrome patients result in altered deposition of elastic fibers in skin and a subclinical dermal phenotype

Williams syndrome (WS) is a complex developmental disorder with multisystem involvement known to be the result of a microdeletion in the q11.23 region of chromosome 7. This deletion involves several genes, including the elastin gene. Although elastic fibers are important constituents of skin, little is known about the skin phenotype in WS patients. We have therefore studied the skin of four WS patients in which we've shown the deletion of one copy of the elastin gene. Physical examination and indirect immunofluorescent microscopy of elastin did not detect any major phenotypic or morphologic changes in the skin. We were able, however, to show subtle textural changes in skin and, by electron microscopy, that the amorphous component of elastic fibers in WS patients was consistently reduced when compared to normal controls. These findings indicate that deletion of one copy of the elastin gene results in reduced deposition of elastin in dermal elastic fibers, an altered elastic fiber ultrastructure, and a subclinical dermal phenotype in the children and young adult patients analyzed in this study.

A new locus for autosomal dominant congenital cataracts maps to chromosome 3

PURPOSE

To map a gene for cataracts in a family with congenital nuclear and sutural cataracts and to examine candidate genes in the linked region.

METHODS

A large family with autosomal dominant congenital nuclear and sutural cataracts was identified and characterized. A genome-wide screen was conducted with a set of markers spaced at 10- to 15-cM intervals, and linkage was assessed using standard LOD score analysis.

RESULT

Fifteen (15) affected individuals were identified. This form of congenital cataracts maps to a 12-cM region on chromosome 3q21.2-q22.3 between markers D3S3674 and D3S3612, with a maximum multipoint LOD score of 6.94 at D3S1273. The crystallin gene, CRYGS, was excluded as a candidate gene for this locus.

CONCLUSIONS

There are now more than 12 different genetic loci that cause congenital cataracts. The most recent locus to be identified is on chromosome 3q21.2-q22.3, in a family with congenital nuclear and sutural cataracts.

Rapid-onset dystonia-parkinsonism: linkage to chromosome 19q13

Rapid-onset dystonia-parkinsonism (RPD) is an autosomal dominant movement disorder characterized by sudden onset of persistent dystonia and parkinsonism, generally during adolescence or early adulthood. Symptoms evolve over hours or days, and generally stabilize within a few weeks, with slow or no progression. Other features include little or no response to L-dopa, and low levels of homovanillic acid in the central nervous system. Neuroimaging studies indicate no degeneration of dopaminergic nerve terminals in RDP, suggesting that this disorder results from a functional deficit, as in dystonia, rather than neuronal loss, as in Parkinson's disease. We studied 81 members of two midwestern US families with RDP, 16 of whom exhibited classic features of RDP. We found significant evidence for linkage in these two families to markers on chromosome 19q13, with the highest multipoint LOD score at D19S198 (z = 5.77 at theta = 0.0). The flanking markers D19S587 and D19S900 define a candidate region of approximately 8 cM. Although RDP itself is a rare condition, it is important because it has clinical and biochemical similarities to both Parkinson's disease and dystonia. Identification of the genetic defect in RDP holds promise for understanding the underlying disease processes of both of these more common diseases.

The differentiation of cerebellar interneurons is independent of their mitotic history

A narrow time window centered around the terminal mitosis of their precursors has been recognized to be critical for the determination and/or realization of the developmental fate of a variety of neuronal phenotypes. In contrast, individual cell lineages in the cerebellum get separated early during embryonic development, and at least precursors for granule neurons have been found to be specified while still proliferating. We utilized primary dissociated cultures to address the issue of whether the faithful development of cerebellar granule cells and basket/stellate cells is dependent on their mitotic history and on the completion of a fixed number of cell cycles. Neuroblasts derived from embryonic cerebellar anlagen and transferred into primary dissociated cultures stopped proliferating as assessed by a loss of expression of the cell proliferation marker, Ki-67, and a failure to incorporate 5-bromo-2'-deoxyuridine. Although these cells had been forced to leave the proliferating cell pool prematurely, they developed into granule neurons or basket/stellate cells as judged by their distinct pattern of expression of specific molecular markers and the acquisition of a typical morphology. This included the cell intrinsic capacity of granule neurons to position their afferent synapses specifically to their dendrites. Thus, the competence of cerebellar interneurons to differentiate appropriately is independent of the precise timing of their final mitosis; however, their sensitivity towards extrinsic developmental signals appears to vary in a cell cycle-dependent manner, as suggested by the failure to survive of those cells that were in S-phase at the time of cultivation.

GLC1F, a new primary open-angle glaucoma locus, maps to 7q35-q36

BACKGROUND

A large family with adult-onset primary open-angle glaucoma (POAG) was identified.

OBJECTIVE

To initiate a genome-wide scan to map the POAG locus in this family.

METHODS

Blood samples or buccal swabs were obtained from 25 members of a large family with POAG after informed consent was obtained. Members and their spouses were evaluated clinically for POAG on the basis of intraocular pressures, cupping of discs, and visual fields. DNA samples were used for a genome-wide screen using microsatellite markers.

RESULTS

Ten affected family members in 4 generations showed evidence of POAG including intraocular pressures of 22 mm Hg or more, and/or optic cup-disc ratios of 0.6 or more, and/or visual field defects consistent with glaucomatous damage. Primary open-angle glaucoma segregated as an autosomal dominant trait, with the disease locus mapping to 7q35-q36 between markers D7S2442 and D7S483 with a multipoint lod score of 4.06.

CONCLUSION

A sixth gene for POAG (GLC1F) has been mapped to 7q35-q36 in a family with at least 4 generations affected.

CLINICAL RELEVANCE

The mapping of this locus further confirms that primary open-angle glaucoma is a heterogeneous group of diseases with at least 6 different loci resulting in a similar phenotype. The eventual ability to classify which major POAG gene an affected person carries could have ramifications for selecting the most effective treatment regimen for that person.

Software implementation of statistical methods for the analysis of structure and patterns in neuroanatomical objects

Neuroanatomical research has greatly benefited from the availability of a large number of cell-specific and region-specific molecular markers. In fact, the analysis of spatial patterns of gene expression in individual cells or patterns within cell populations often provides an inroad into understanding the functional significance of distinct structures. However, it can be difficult to discern whether the arrangement of different morphologically or biochemically defined structures represents a defined pattern. To address this issue, we adapted a series of established statistical procedures for the analysis of uni- and bivariate point patterns in histological specimens. We implemented these statistical procedures in an easy-to-use computer program. The methods are scale independent and easy to expand for various applications. The utility of this approach is demonstrated with examples from tissue sections and cultured cells at the light and electron microscopical levels.

From zebra stripes to postal zones: deciphering patterns of gene expression in the cerebellum

The analysis of patterned gene expression has been an important tool for dissecting the molecular and developmental bases of functional compartmentalization in the mammalian cerebellum. In particular, sagittally-oriented cellular aggregates arranged along the mediolateral axis are the patterning element most commonly invoked to illustrate cerebellar compartmentalization, and these are revealed both by patterns of afferent projection and by a number of classical biochemical markers that are distributed in a pattern of'zebra stripes'. Compartmentation along both the mediolateral and rostrocaudal axes might be linked mechanistically to segmentation in the fruit fly, since early cerebellar development is especially dependent upon the expression of mammalian homologs of Drosophila segmentation genes. In addition, as has been demonstrated in the retinotectal system, some of these genes are likely to control positional information required for the sagittal organization of cerebellar afferent projections. However, in contrast to these global or macro zones, the cerebellum is also compartmentalized at the subcellular or micro level. This can be visualized by differential patterns of mRNA distribution within the sole cerebellar efferent system, the Purkinje cell, defining within such cells a number of distinct subcellular domains or 'postal zones'. The global versus subcellular levels of cerebellar compartmentalization are related since they both appear to be linked to patterns of afferent innervation.A major goal of cerebellar research will be to unravel the true nature of such a relationship, and its relevance to function and behavior.

Development and fine structure of murine Purkinje cells in dissociated cerebellar cultures: neuronal polarity

Cerebellar Purkinje cells (PC) display a highly distinctive form of polarity. We have cultured murine PCs from dissociated E16 cerebellar anlagen for 1 week to investigate the early stages of neuronal compartmentalization and synaptic interactions, features which are important for the establishment of neuronal polarity. To unequivocally identify the PCs we utilized light and electron microscopic immunocytochemistry with an anti-serum to the cell class-specific marker L7/pcp2 gene product. The PCs typically show a single, long axon, numerous short appendages classified as filopodia and protospines, and a small number of protodendrites. The nucleus is positioned asymmetrically in both the horizontal and vertical axes of the soma. The Golgi apparatus, coated and uncoated vesicles, and mitochondria are prominent ultrastructural features, while the endoplasmic reticulum is highly fragmented. The cell body receives rudimentary synapses on its smooth surfaces and appendages and no consistent morphological differences were detected between these elementary contacts. The axon is clearly identifiable; it emanates from either the cell body or a protodendrite, bifurcates at predominantly right angles, forms beaded collaterals, and terminates with relatively large growth cones. The varicosities of the PC axon contain pleomorphic synaptic vesicles and form rudimentary synapses primarily with the dendritic shafts of immunonegative neurons. The protodendrites are short, quickly tapering and sparsely branched; they emit numerous filopodia and immature spines and terminate with small growth cones. Rudimentary synapses are received on the proximal dendritic shafts and filopodia, and more mature synapses occur frequently on protospines. With few exceptions, PCs lie atop an astrocytic bed layer and glial processes are apposed to the various aspects of the PC body left free by the afferent axons. By contrast, PC processes are largely free of glial sheaths. We conclude that the "stellate stage" of PC development in situ is replicated rather faithfully in culture and that PCs have established polarity and have begun to form intercellular contacts by 1 week in vitro. Moreover, the PCs are already morphologically distinct from other cell types in the 1 week cultures, although they have yet to develop the differentiated features that distinguish mature PCs.