Polymorphisms in the human DNA ligase I gene (LIG1) including a complex GT repeat.

Sequencing of a human DNA ligase I cDNA clone derived from HeLa cells revealed two unreported differences with the published sequence: a single base change and a three-base deletion. Both differences are in exon 6, and were analyzed by amplifying a segment containing exon 5, intron 6, and exon 6. The first finding was that intron 6 is approximately 2.

Functional expression of two KvLQT1-related potassium channels responsible for an inherited idiopathic epilepsy.

Benign familial neonatal convulsions (BFNC), a class of idiopathic generalized epilepsy, is an autosomal dominantly inherited disorder of newborns. BFNC has been linked to mutations in two putative K+ channel genes, KCNQ2 and KCNQ3. Amino acid sequence comparison reveals that both genes share strong homology to KvLQT1, the potassium channel encoded by KCNQ1, which is responsible for over 50% of inherited long QT syndrome.

Dominant-negative KvLQT1 mutations underlie the LQT1 form of long QT syndrome.

Background: Mutations that map to the KvLQT1 gene on human chromosome 11 account for more than 50% of inherited long QT syndrome (LQTS). It has been discovered recently that the KvLQT1 and minK proteins functionally interact to generate a current with biophysical properties similar to I(Ks), the slowly activating delayed-rectifier cardiac potassium current. Since I(Ks) modulates the repolarization of cardiac action potentials it is reasonable to hypothesize that mutations in KvLQT1 reduce I(Ks), resulting in the prolongation of cardiac action potential duration.

KvLQT1, a voltage-gated potassium channel responsible for human cardiac arrhythmias.

The clinical features of long QT syndrome result from episodic life-threatening cardiac arrhythmias, specifically the polymorphic ventricular tachycardia torsades de pointes. KVLQT1 has been established as the human chromosome 11-linked gene responsible for more than 50% of inherited long QT syndrome. Here we describe the cloning of a full-length KVLQT1 cDNA and its functional expression.

Radical hysterectomy for invasive cervical cancer. A 25-year prospective experience with the Miami technique.

Background: The Miami modification of the traditional Wertheim-Meigs radical hysterectomy was used to treat Stage IB-IIA cervical cancer in a 25-year prospective study involving 978 patients.

Methods: The modifications included: vaginal reconstruction and closure using bladder and rectosigmoid serosa, retroperitoneal drainage through abdominal suction catheters, and suspension of the denuded ureters with the ipsilateral obliterated hypogastric artery.

Results: The overall corrected 5-year survival rate was 90.

Development and in vitro evaluation of an intra-oral controlled-release delivery system for chlorhexidine.

Copolymers of hydroxyethyl methacrylate (HEMA) and methyl methacrylate (MMA) were prepared and used to fabricate a membrane-controlled reservoir-type controlled-release delivery system for chlorhexidine that should be suitable for intra-oral use. The reservoir of the system was prepared by softening an 80:20 mixture of chlorhexidine diacetate and 50:50 HEMA:MMA copolymer with methyl ethyl ketone (MEK), and pressing standard amounts of the resulting dough-like mixture into silicone rubber molds. A membrane was applied to the reservoirs by rotating them through a solution of 30:70 HEMA:MMA copolymer in MEK.

Expression of asparagine independence in variants of ICR 2A haploid frog cells.

Properties of the change from asparagine dependence (asn-) to independence (asn+) were investigated in the androgenetic haploid frog cell line ICR 2A. Two types of asn+ variants arose spontaneously during culture. Glutamine-dependent asparagine synthetase (AS) activity, found to be deficient in asn- cells, was repressed by asparagine in one type of variant and expressed constitutively in the other.

Experimental constraints on theories of high-transition temperature superconductors.

Recent experiments have revealed several key features of the unique nature of the new, high-transition temperature cuprate superconductors. These results provide an easily understandable, physical picture of the structure and behavior of the charge carriers in these materials, and point to the mechanism responsible for their existence. These experiments are now placing strong constraints on possible theoretical models of the phenomenon.

Gap-modulation infrared spectroscopy of high transition temperature superconductors.

Conventional methods of determining the coupling factor alpha(2)(omega)F(omega) for the newly discovered high transition temperature (T(c)) cuprate superconductors by using tunneling and infrared measurements have thus far failed to show the cause of the very high T(c) of these compounds. This is due in part to difficulties in sample preparation for tunneling studies and to difficulties in obtaining good data at relatively high tunneling voltages. Also, in IR (infrared) measurements, small differences in absorptivity between the normal and superconducting state can be masked by changes in the phonon occupation at high and low temperatures.

Effects of octenidine on dental plaque and gingivitis in monkeys.

This investigation monitored the effects of daily oral rinses with octenidine on plaque and gingivitis in five monkeys. Formulations containing 0.5% or 1.

Conductive polymers derived from iron, ruthenium, and osmium metalloporphyrins: The shish-kebab approach.

The synthesis and characterization of pyrazine-bridged polymers of iron(II/III), ruthenium(II/III), and osmium(II/III) octaethylporphyrin (dubbed "shish-kebab" polymers) are presented. Optical and dc conductivity measurements reveal that the ruthenium and osmium polymers, when partially oxidized, are highly conductive. Electrochemical and ESR results are presented that indicate the existence of an interesting metal-centered conduction pathway.

Effect of antibody preparations on glucose uptake by a cariogenic Streptococcus.

The effect of antisera to whole cells or cell wall components on glucose uptake by S. mutans 6715 was examined. Early stationary phase 6715 cells were treated with test serum and incubated at 37 degrees C in the presence of 14C-glucose.

Prevalence of Streptococcus mutans serotypes, Actinomyces, and other bacteria in the plaque of children.

Selected microbial components in dental plaque were determined for children in Biddeford, Maine and Colombia, South America. Using cultural methods, Streptococcus mutans was detected in 51.4% of the Colombian children and 63.

Antibiotic susceptibility of Streptococcus mutans: comparison of serotype profiles.

A total of 82 strains of Streptococcus mutans representing serotypes a through g were tested for susceptibility to erythromycin, penicillin, methicillin, lincomycin, tetracycline, vancomycin, gentamicin, streptomycin, neomycin, kanamycin, bacitracin, and polymyxin B. Strains included stock cultures and isolates from human and animal dental plaque. Minimal inhibitory concentrations were determined by a broth-microdilution procedure.

Comparative recovery of Streptococcus mutans on ten isolation media.

The ability of Streptococcus mutans (Bratthall serotypes a through e) to grow on 10 isolation media was examined. The number and morphology of the colonies were observed to vary on different media. The use of blood-sucrose media consistently produced the highest recoveries.

Dynamics of adenosine-3', 5'- monophosphate transfer among mother, fetus, and amniotic fluid in the rhesus monkey.

Cyclic AMP exchange among the mother, amniotic fluid, and fetus was studied in normal rhesus monkeys at term pregnancy. Following a pulse intravenous administration of 3H-cyclic AMP into the mother, a small fraction of the dose appeared in less than 1 minute in fetal blood. It appeared in the amniotic fluid after 5 minutes and reached maximum level in 20 minutes.

Current aspects of sterilization. The selection and application of various surgical methods of sterilization.

A partial analysis of 4,270 female sterilizations performed during a 7 year time period was described as related to changing patterns of application according to a sterilization program. Special attention was given to such factors as type of procedure, reasons for selection of procedures, ancillary conditions, mortality rate, and follow-up. A plea is made for accuracy when a sterilization is truly used as the primary indication for surgery and for flexibility and individualization in the application of sterilization techniques.

A new immunoassay based on fluorescence excitation by internal reflection spectroscopy.

A new immunoassay technique is described which uses totally internally reflected light to excite the fluorescence of fluorescein labeled antibody which has become bound to a hapten--protein conjugate absorbed on a quartz-plate in the antibody solution. The presence of any free hapten in solution reduces the amount of antibody free to bind to the surface and thus reduces the fluorescence signal. Measurement of the decrease of the fluorescent signal then gives a measure of the concentration of free hapten present.