beta, gamma-Peroxy analogs of adenosine and guanosine triphosphate: synthesis and biological activity.

Extended analogs of adenosine triphosphate (ATP) and guanosine triphosphate (GTP), in which a peroxide bridge replaces the terminal bridge-oxygen of the triphosphate chain, have been synthesized. The ability of beta, gamma-peroxy-ATP to inhibit or substitute for ATP in representative enzyme systems and that of beta, gamma-peroxy-GTP, for FTP in protein synthesis was tested.

A fluorescent modification of adenosine triphosphate with activity in enzyme systems: 1,N 6 -ethenoadenosine triphosphate.

A new, highly fluorescent adenosine triphophate (ATP) analog, 1,N(6) ethenoadenosine triphosphate, has been synthesized. Its fluorescence properties, including the long fluorescence lifetime and the possibility of detection at very low concentrations, in conjunction with its activity in the representative enzyme systems here reported, make it a valuable probe of enzymic mechanism and structure.

Defined dimensional changes in enzyme cofactors: fluorescent "stretched-out" analogs of adenine nucleotides.

A concept is presented for testing the dimensional restrictions of enzyme-active sites by stretching the substrate or cofactor by known magnitude. These restrictions of enzyme-active sites specific for purine cofactors were tested by the synthesis and evaluation of lin-benzoadenosine 5'-triphosphate, 5'-diphosphate, and 3',5'-monophosphate with respect to enzyme binding and activity. These "stretchedout" (by 2.4 angstroms) versions of the adenine ribonucleotides bind strongly, slow the enzymatic rates, and have useful fluorescence properties.

Cytokinin from soluble RNA of Escherichia coli: 6-(3-methyl-2-butenylamino)-2-methylthio-9-beta-D-ribofuranosylpurine.

We have isolated a compound responsible for the cytokinin activity of soluble RNA from Escherichia coli. The structure, indicated as 6-(3-methyl-2-butenylamino)-2-methylthio-9-beta-D-ribofuranosylpurine, C(16)H(23)N(5)0(4)S, on the basis of low-and high-reso!ution mass spectrometry, was established by unequivocal synthesis. The mass spectra, chromatographic behavior, and ultraviolet spectra of the compounds from natural and synthetic sources were identical.

Cytokinin of wheat germ transfer RNA: 6-(4-hydroxy-3-methyl-2-butenylamino)-2-methylthio-9-beta-D-ribofuranosylpurine.

A new modified nucleoside is responsible, in part, for the cytokinin activity of transfer RNA from wheat germ. The structure as judged by mass spec-trometry is 6-(4-hydroxy-3-methyl-2-butenylamino)-2-methylthio-9-beta-D-ribofuran-osylpurine. Unequivocal synthesis afforded material having ultraviolet, mass spectral, and chromatographic properties identical with those of the natural product.

Fluorescent modification of adenosine 3',5'-monophosphate: spectroscopic properties and activity in enzyme systems.

The synthesis of a highly fluorescent analog of adenosine 3',5'-monophosphate, namely, 1,N(6)-ethenoadenosine 3',5'-monophosphate, has provided a powerful probe for systems involving adenosine 3',5'-monophosphate. The potential utility of this analog is indicated by its long fluorescent lifetime, detectability at low concentration, and relatively long wavelength of excitation (300 nanometers). In protein kinase systems it is a highly acceptable substitute for adenosine 3',5'-monophosphate.

Patterning micron-sized features in a cross-linked poly(acrylic acid) film by a wet etching process.

This paper describes a photolithographic method to create sub-micron-scale patterns of cation-cross-linked poly(acrylic acid) (CCL-PAA). PAA can be cross-linked with a wide range of metal cations-including, but not limited to, Ag, Ca, Pd, Al, La, and Ti. Upon patterning a positive photoresist (diazonaphthoquinone-novolac resin) on a film of CCL-PAA, the exposed regions of CCL-PAA were etched by either an aqueous NaOH or EDTA solution. The initial cross-linking cation could be exchanged for a second cation that could not be patterned photolithographically. We used these patterned films of CCL-PAA i) to host and template the reduction of metallic cations to metallic nanoparticles, and ii) to fabricate porous, low- dielectric substrates.

3-Substituted adenines. In vitro enzyme inhibition and antiviral activity.

The direct alkylation of adenine at the 3 position has been extended to produce series of 3-alkyl-, 3-allyl-, and 3-(substituted benzyl)adenines. When these compounds were tested for enzyme inhibition and antiviral activity in vitro, 3-n-pentyladenine was found to be the most active compound in inhibiting the enzyme dopamine-beta-hydroxylase, and 3-(2-bromobenzyl)adenine showed the most striking inhibition of multiplication of Vaccinia virus and of Herpes simplex virus in tissue culture.

A second patient with MCA/MR syndrome with multiple circumferential skin creases.

Symmetrical congenital circumferential skin creases are a rare feature described in only a few conditions. We report a case of a 29-month-old boy with symmetrical circumferential skin creases on arms, legs, and digits, and other features reminiscent of the single case reported by Cohen et al. [1993: Clin Dysmorphol 2:39-46] and reviewed by Elliott et al. [1996: Am J Med Genet 62:23-25]. The key features also include epicanthic folds, microphthalmia, microcornea, microcephaly, small, low-set posteriorly angulated ears with thick overfolded helices, cleft palate, and moderate-severe psychomotor developmental delay.

Diploid/tetraploid/t(1;6) mosaicism in a 17-year-old female with hypomelanosis of Ito, multiple congenital anomalies, and body asymmetry.

Many types of chromosome mosaicism have been identified in cases of hypomelanosis of Ito, often in association with chromosome instability; however, there have been very few cases with diploid-tetraploid mosaicism described in the literature. We present a patient with a tetraploid mosaicism: a 17-year-old girl who has hypomelanosis of Ito in association with diploid/tetraploid/t(1;6) mosaicism. She had multiple congenital anomalies of omphalocele, exstrophy of bladder, duodenal web, and imperforate anus. These features have not been described previously in diploid-tetraploid mosaicism.

Terminal deletion of chromosome 10q at band 26.1: follow-up in an adolescent male with high-output renal failure from congenital obstructive uropathy.

We report on the clinical findings in an adolescent male with a de novo terminal deletion of chromosome 10 del(10)(q26.1). This young man is one of the oldest known patients reported with this condition. His condition is compared with that of 11 reported cases of de novo terminal deletion of 10q at band 26. Individuals with chromosome 10q26 deletion have some findings and medical complications in common. Our patient has chronic renal failure due to urinary tract obstruction from posterior urethral valves. Similar anomalies have been reported in cases of 10q26 deletion, suggesting a careful renal/urinary tract evaluation should be completed in individuals with this condition.

Two pairs of male monozygotic twins discordant for Wiedemann-Beckwith syndrome.

Wiedemann-Beckwith syndrome (WBS) is a congenital anomaly syndrome which classically consists of exomphalos, macroglossia, and gigantism. The syndrome is also associated with a variety of minor anomalies and affected individuals have an increased risk of developing rare embryonal cell tumors. To date, 15 monozygotic (MZ) twin pairs have been reported of which 13 are discordant for WBS. All except one pair of the discordant WBS twin pairs have been female. We report two pairs of male MZ twins, each discordant for WBS.

Polytopic anomalies with agenesis of the lower vertebral column.

We describe clinical, pathological and radiological findings in 15 cases of sporadic and familial lower spine agenesis with additional anomalies of the axial skeleton and internal organs and speculate about the cause and pathogenesis of this malformation complex. We show that all of these findings are defects of blastogenesis, originate in the primary developmental field and/or the progenitor fields, thus representing polytopic field defects. This concept appears applicable in our cases and makes such terms such as "caudal regression syndrome" or "axial mesodermal dysplasia spectrum" redundant.

Analysis of chromosomal abnormalities in human sperm after chemotherapy by karyotyping and fluorescence in situ hybridization (FISH).

The frequency of numerical and structural chromosomal abnormalities was studied in the sperm of a lymphoma patient 3 years after MACOP-B chemotherapy (CT). Sperm karyotyping was performed by fusion of human sperm with hamster oocytes and analysis of 193 Q-banded sperm chromosomes. Multicolor fluorescence in situ hybridization (FISH) was performed on 10,228 sperm for analysis of disomy frequencies for chromosomes 1 and 12 and on 10,664 sperm for chromosomes X and Y. Sperm karyotyping demonstrated numerical abnormalities in 7.3% of the spreads, 6.7% hypohaploid and 0.5% hyperhaploid, giving a conservative estimate of aneuploidy of 1%. Structural chromosomal abnormalities were present in 7.3% of the karyotypes and 0.5% had both numerical and structural abnormalities. Results of FISH analyses yielded disomy frequencies of 0.10%, 0.11%, 0.04%, 0.05%, and 0.18% for chromosomes 1, 12, X, Y, and XY, respectively. The frequency of diploid sperm was 0.09%. The frequency of abnormalities was not significantly increased compared to control donors for any of the studies. Also, the frequencies of X- and Y-bearing sperm did not differ significantly from 50% in the sperm karyotyping or FISH studies.

Behavior of free-ranging and captive American kestrels under electromagnetic fields.

Wild birds, particularly raptors, commonly use electrical transmission structures for nesting, perching, hunting, and roosting. Consequently, birds are exposed to electromagnetic fields (EMFs). The amount of time that wild reproducing American kestrels (Falco sparverius) were exposed to EMFs was determined, and the effects of EMFs on the behavior of captive reproducing kestrels were examined. Wild kestrels were exposed to EMFs for 25% to 75% of the observed time. On a 24-h basis, estimated EMF exposure of wild kestrels ranged from 71% during courtship, to 90% during incubation, similar to that experienced by captive kestrels (88% of a 24-h period). Additionally, captive kestrels were exposed to EMF levels experienced by wild kestrels nesting under 735-kV power lines. Captive EMF females were more active, more alert, and perched on the pen roof more frequently than control females during courtship. EMF females preened and rested less often during brood rearing. EMF male kestrels were more active than control males during courtship, and more alert during incubation. Increased activity of kestrels during courtship may be linked to changes in corticosterone, but likely not melatonin. Observed behavioral changes were unlikely to directly result in the better growth of nestlings and fledging success, or poorer hatching success, of the EMF group, as previously reported. Behavioral changes of captive EMF kestrels may be observed in wild kestrels.

Preparation and characterization of polyclonal and monoclonal antibodies specific for covalently linked DNA/RNA cross sections.

Covalently linked cross sections refer to structures that mimic hydrogen-bonded purine-pyrimidine, purine-purine, and pyrimidine-pyrimidine duplexes. Cross sections dA [symbol:see text] U and A [symbol: see text] dT, which have been synthesized chemically, have molecular dimensions similar to purine-pyrimidine base pairs in a double helix. We propose that antibodies to such covalent cross sections might facilitate the study of the pathogenesis of specific diseases or of biochemical processes in which base pair involvement is suspected and/or demonstrated. We have made polyclonal antibodies against "A:U" and "A:T" cross sections by immunizing rabbits with dA [symbol: see text] U and A [symbol: see text] dT, each conjugated to keyhole limpet hemocyanin (KLH). The antibodies were found to be highly specific for the cross sections and to cross react minimally to single nucleosides. Hybridomas secreting monoclonal antibodies to "A:T" were then generated from spleen cells of mice immunized with A [symbol: see text] dT conjugated to KLH. The MAbs produced were also found to be highly specific for "A:T" among various nucleosides. In fact, the binding of most of the monoclonal antibodies to "A:T" was only partially inhibited by high concentrations of adenosine or thymidine. All monoclonal antibodies to "A:T" cross react, but with lower affinity, to "A:U." Selected MAbs showed greater inhibition of binding to "A:T"-BSA by A + T than by A or T alone.

An unknown spondyloepimetaphyseal dysplasia with a positive sweat chloride test, sparse hair and mild facial dysmorphism.

We report the case of a 5-year-old Caucasian female with an undiagnosed spondyloepimetaphyseal dysplasia, mild facial dysmorphism, sparse hair, mild developmental delay and a positive sweat chloride test in the absence of cystic fibrosis.