X-linked progressive mixed deafness: a new microdeletion that involves a more proximal region in Xq21.

We report a large two-generation pedigree with seven affected males segregating for an X-linked mixed conductive sensorineural deafness. The patients present with atypical Mondini-like dysplasia, dilated petrous facial canal, dilatation of the internal auditory meatus fully connected with enlarged cochlear canals, and, in one patient, a wide bulbous posterior labyrinth. Obligatory carrier females are mildly affected. Molecular characterization of this family revealed a deletion of locus DXS169, in Xq21.1. Loci DXS72 and DXS26, which, respectively, flank DXS169 proximally and distally, were intact. Since a gene responsible for X-linked progressive mixed deafness with perilymphatic gusher (DFN3) has previously been assigned by deletion mapping to a slightly more distal interval between DXS26 and DXS121, this study indicates either two different deafness genes or the involvement of a very large region in Xq21.     

Effect of Parental Growth on Dynamics of Conjugative Plasmid Transfer in the Pea Spermosphere

Plasmid transfer rates for the conjugative plasmid R388::Tn1721 from Pseudomonas cepacia (donor) to Pseudomonas fluorescens (recipient) on agar media, in broth, and in microcosms containing sterile or nonsterile soil, in the presence or absence of germinating pea seeds, were determined. Donors, recipients, and transconjugants were enumerated on selective media after 1 day on agar or in broth culture and over a 7-day period in soil or pea spermosphere microcosms. Donor and recipient growth rates and plasmid transfer rate constants [(gamma), where (gamma) = transconjugants (middot) (donors (middot) recipients)(sup-1) (middot) h(sup-1)] were calculated for three initial parental densities (10(sup4), 10(sup6), or 10(sup8) CFU/g or ml) in each system. For all initial density levels, values of (gamma) in agar and broth matings were higher than those in soil or in the pea spermosphere-rhizosphere microcosms. Values of (gamma) were not influenced by the pea spermosphere or by sterile or nonsterile conditions of the soil. However, (gamma) values in microcosm experiments were inversely related to initial parental density and were directly related to donor growth rates. Values of (gamma) averaged 4 x 10(sup-10), 4 x 10(sup-12), and 3 x 10(sup-14) when initial donor and recipient cell densities were 10(sup4), 10(sup6), and 10(sup8) CFU/g, respectively. These results suggest that the plasmid transfer rate constant is independent of parental cell density only when parental growth is not limited. In a resource-limited environment, intra- or interspecific competition may reduce the transfer rate by limiting parental growth.     

Isolation of genomic and cDNA clones encoding bovine poly(A) binding protein II.

cDNA clones for bovine poly(A) binding protein II (PAB II) were isolated. Their sequence predicts a protein of 32.8 kDa, revising earlier estimates of molecular mass. The protein contains one putative RNA-binding domain of the RNP type, an acidic N-terminal and a basic C-terminal domain. Analyses of authentic PAB II were in good agreement with all predictions from the cDNA sequence except that a number of arginine residues appeared to be post-translationally modified. Poly(A) binding protein II expressed in Escherichia coli was active in poly(A) binding and reconstitution of processive polyadenylation, including poly(A) tail length control. The cDNA clones showed a number of potential PAB II binding sites in the 3' untranslated sequence. Bovine poly(A)+RNA contained two mRNAs hybridizing to a PAB II-specific probe. Analysis of a genomic clone revealed six introns in the coding sequence. The revised molecular mass led to a demonstration of PAB II oligomer formation and a reinterpretation of earlier data concerning the protein's binding to poly(A).     

Cloning of cDNAs encoding the 160 kDa subunit of the bovine cleavage and polyadenylation specificity factor.

3'-processing of mRNA precursors depends on several protein factors. One of them, cleavage and polyadenylation specificity factor (CPSF) is required for the cleavage of the mRNA precursor or as well as for the tail elongation reaction. We have obtained complementary DNA encoding the 160 kDa subunit, which had previously been shown to interact with the AAUAAA polyadenylation signal. The cDNAs code for an open reading frame of 1444 amino acids. The translated protein has a calculated molecular weight of 161 kDa and a predicted pl of 6.2. Polyclonal antibodies raised against a bacterially expressed fragment of the cDNA recognise 160 kDa subunit of purified calf thymus CPSF. The sequence contains a possible nuclear localisation signal but none of the known RNA binding motifs. It does, however, show sequence similarities to a UV-damaged DNA binding protein (UVdDb).     

A topoisomerase II cleavage site is associated with a novel mitochondrial DNA deletion

Mitochondrial myopathies and encephalopathies can be caused by nucleotide substitutions, deletions or duplications of the mitochondrial DNA (mtDNA). In one such disorder, Kearns-Sayre Syndrome (KSS), large-scale hetero-plasmic mtDNA deletions are often found. We describe a 14-year-old boy with clinical features of KSS, plus some additional features. Analysis of the entire mitochondrial genome by the polymerase chain reaction and Southern blotting revealed a 7864-bp mtDNA deletion, heteroplasmic in its tissue distribution. DNA sequencing established that the deletion was between nucleotides 6238 and 14103, and flanked by a 4-bp (TCCT) direct repeat sequence. Deletions between direct repeats have been hypothesised to occur by a slipped-mismatching or illegitimate recombination event, or following the DNA cleavage action of topoisomerase II. Analysis of the gene sequence in the region surrounding the mtDNA deletion breakpoint in this patient revealed the presence of putative vertebrate topoisomerase II sites. We suggest that direct repeat sequences, together with putative topoisomerase II sites, may predispose certain regions of the mitochondrial genome to deletions.     

New chromosomal translocations correlate with specific immunophenotypes of childhood acute lymphoblastic leukemia

Cytogenetic analysis of leukemic cells obtained at diagnosis from 122 patients with childhood acute lymphoblastic leukemia (ALL) disclosed chromosomal translocations in 36 cases. Two new nonrandom translocations were identified and found to be associated with specific immunophenotypes of the disease. The first, identified in 4 of 16 cases of T-cell ALL positive for sheep erythrocyte receptors (E+), involved the short arm (p) of chromosome 11 and the long arm (q) of chromosome 14 and was designated t(11;14) (p13;q13). The second, found in 7 of 23 cases with a pre-B-cell phenotype, involved the long arm of chromosome 1 and the short arm of chromosome 19; it was designated t(1;19) (q23;p13.3). A third abnormality involving a common breakpoint on chromosome 12 (band p 12) was also identified. These two new differentiation-specific translocations suggest a mechanism for aberrant expression of genes that influence lymphoid cell growth and development, as well as leukemogenesis.     

The passage of orally fed proteins from mother to foetus in the rat

Pregnant rats were orally fed with a mixture of bovine IgG, bovine albumin, ovalbumin and beta-lactoglobulin. Using immunoprecipitation methods, these proteins were detected in the maternal blood serum, urine and uterine fluids, and also in the foetal blood serum and the amniotic fluid. The results imply that a variety of dietary proteins, still immunoprecipitable, are able to cross the materno-foetal barriers to be detected in the foetal circulation, where they may influence the maturation of the immune system of the foetus.     

Distribution of myosin and the glial fibrillary acidic protein (GFA Protein) in rat spinal cord and in the human frontal cortex as revealed by immunofluorescence microscopy

Summary The glial fibrillary acidic (GFA) protein and myosin were localized in rat spinal cord and human frontal cortex using specific antibodies against GFA protein from human spinal cord and highly purified smooth myosin from chicken gizzard by means of an indirect immunofluorescence microscopical approach. A strong GFA protein and myosin immunoreactivity was found in astrocytes of the white and grey matter and in the external glial limitans membrane. The very fine branches of astrocytic processes stained with antiGFA protein, but not with anti-myosin. Similar results were obtained with the human frontal cortex, where myosin antibodies failed to reveal the very fine branches of protoplasmic astrocytes.As a whole, staining with the GFA protein antiserum was more crisp than with the myosin antibody.Thanks are due to Professor J.R. Wolff, Max-Planck Institute for Biophysical Chemistry, Göttingen, for stimulating discussions, to Ursula König, Christa Mahlmeister and Renate Steffens for skilful technical assistance, and to Heidi Waluk for the photographic workSupported by grants from Deutsche Forschungsgemeinschaft (Br 634/1, Dr 91/1, Un 34/4, Ste 105/19)Dedicated to Prof. Dr. med. H. Leonhardt on the occasion of his 60. birthday     

Construction of Texas coastal foredunes with sea oats (Uniola paniculata) and bitter panicum (Panicum amarum)

Studies were conducted on Padre Island, Texas since 1968 to provide specifications for how to use vegetation to reconstruct destroyed portions of foredunes of Gulf Coast barrier islands. The area has a subtropical, semi-arid climate, moderated by maritime tropical air from the Gulf of Mexico. Annual precipitation averages 670 mm for the island. We established experimental foredunes in broad overwash areas, 1.5 m M.S.L. where foredunes were eroded by hurricanes or destroyed by blowouts and across hurricane overwash channels of lower elevation behind the berm and more susceptible to surges. Most successful establishment of a vegetated dune was by transplanting directly onto the level backbeach to reestablish the original duneline about 125 meters inland. Sea oats and bitter panicum proved best of all species tested. Bitter panicum was the more desirable because of higher transplant survival, a longer planting season, and ease of harvest. Transplant survival was influenced more by soil salinity, soil moisture, and plant vigor, than by planting season as successful plantings occurred during all seasons. December through February plantings were best for sea oats, but survival of bitter panicum transplants different little from November through May. Both species are capable of growth year round during periods of favorable climatic conditions, although little growth occurs from mid-December to mid-February. Transplants placed 0.6 m apart with total planting width of 15 m produced foredunes nearly 6 m high in 6 years. Such plantings trapped sand at the rate of 12.5 m³/m of beach. In hurricane overwash channels, we used 0.6 m high sand fence placed 3 m apart to produce a flat topped dune free of salt for a planting surface. Without this site preparation, no transplants survived due to high soil salinity. Dune width was effectively widened by planting a strip 15 m wide immediately beachward of a previously established 4-year old dune.Presented at the Seventh International Biometeorological Congress, 17–23 August 1975, College Park, Maryland, USA.     

Hereditary mucoepithelial dysplasia: a disease apparently of desmosome and gap junction formation.

A previously unrecognized autosomal dominant syndrome affecting oral, nasal, vaginal, urethral, anal, bladder, and conjunctival mucosa with cataracts, follicular keratosis, nonscarring alopecia, and terminal lung disease is described in a four-generation kindred of German extraction. Severe photophobia, tearing, and nystagmus in infancy heralds the development of keratitis, corneal vascularization, and lens cataracts. Repeated corneal transplants have failed. Red, periorificial mucosal lesions involving the above structures are noted by 1 year of age and may persist throughout life. Chronic rhinorrhea and repeated upper respiratory infections frequently progress to bilateral pneumonia accompanied by loss of hair, diarrhea, occasional melena, enuresis, pyuria, and hematuria. Spontaneous pneumothorax is frequent, terminating in fibrocystic-type lung disease and cor pulmonale. Women have had repeated abnormal vaginal PAP smears. Histologically the mucosal epithelium shows dyshesion, thinning of the epithelial layer, and dyskeratosis. Mucosal PAP smears show lack of epithelial maturation, cytoplasmic vacuoles and inclusions, and individual cell dyskeratosis. Histochemically there is a lack of cornification and keratinization. Ultrastructural studies show lack of keratohyalin granules, a paucity of desmosomes, intercellular accumulations, cytoplasmic vacuolization, and formation of bands and aggregates of filamentous fibers and structures in the cytoplasm resembling desmosomes and gap junctions. The condition is probably a panepithelial cell defect of desmosomal and gap junction structure most prominently affecting mucosal epithelia associated with an increased susceptibility to a variety of adventitious organisms.