Oral colonization of Streptococcus mutans in six-month-old predentate infants.

We hypothesize that S. mutans colonization occurs more frequently in pre-term children due to their relative immaturity. In this study of 172 predentate, six-month-old infants, we found that 50% of pre-term and 60% of full-term children harbored S.

Multi-layered microcapsules for cell encapsulation.

Mechanical stability, complete encapsulation, selective permeability, and suitable extra-cellular microenvironment, are the major considerations in designing microcapsules for cell encapsulation. We have developed four types of multi-layered microcapsules that allow selective optimization of these parameters. Primary hepatocytes were used as model cells to test these different microcapsule configurations.

Association of Streptococcus mutans infection and oral developmental nodules in pre-dentate infants.

Since dental caries may present soon after tooth eruption, we hypothesized that colonization of Streptococcus mutans can occur in the predentate stages. In this study, we examined S. mutans colonization and its association with oral developmental nodules (Bohn's nodules) in 60 pre-term and 128 full-term, three-month-old infants.

A new nerve guide conduit material composed of a biodegradable poly(phosphoester).

There is a resurgence of interest in the development of degradable and biocompatible polymers for fabrication of nerve guide conduits (NGCs) in recent years. Poly(phosphoester) (PPE) polymers are among the attractive candidates in this context, in view of their high biocompatibility, adjustable biodegradability, flexibility in coupling fragile biomolecules under physiological conditions and a wide variety of physicochemical properties. The feasibility of using a biodegradable PPE, P(BHET-EOP/TC), as a novel NGC material was investigated.

Fabrication of poly(phosphoester) nerve guides by immersion precipitation and the control of porosity.

Immersion precipitation was employed as a method for the fabrication of polymeric conduits from P(BHET-EOP/TC), a poly(phosphoester) with an ethylene terephthalate backbone, to be applied as guidance channels for nerve regeneration. Coatings of various porosities could be obtained by immersing mandrels coated with a solution of the polymer in chloroform into non-solvent immersion baths, followed by freeze or vacuum-drying. The porosity of the coatings decreased with an increase in polymer molecular weight, drying time before precipitation and concentration of polymer solution.

Insecticidal activity of essential oils to the tobacco cutworm, Spodoptera litura.

Twenty-one essential oils were tested for insecticidal activity via topical administration to third instar larvae of the tobacco cutworm, Spodoptera litura. Oils of Satureia hortensis, Thymus serpyllum and Origanum creticum produced >90% larval mortality at 24 h at a dose of 100 microg per larva. The LD(50) value for S.

[Effects of insulin on production of NO and NOS mRNA expression in bovine aortic endothelial cells].

Aim: In order to explore the regulation of the production of nitric oxide (NO) and the expression of nitric oxide synthase (NOS) gene in bovine aortic endothelial cells (BAEC) by insulin.

Methods: The NO2- which is the production of NO in the culture medium was determined based on Griess reaction. Quantitative RT/PCR technique was performed to quantitate the levels of NOS mRNA in BAEC.

Investigation of colonic disease.

Bowel cancer awareness among the general public has heightened in recent years. The promotion of prompt referral and the pressure on early diagnosis will alter our previous strategies on colonic evaluation. This article gives an overview of the colonic investigations currently available.

Use of telemedicine in undergraduate teaching of surgery.

Telemedicine as an undergraduate teaching method was evaluated by exposing medical students to outpatient videoconferencing. Forty clinical students on a 10-week surgical rotation participated in the study. Telemedicine sessions involved videoconferencing from the general surgical outpatient department located in a sister hospital 8 km away, using a roll-about system connected by ISDN at 384 kbit/s.

A controlled study of the morphometric changes in the primary dentition of pre-term, very-low-birthweight children.

The aim of the present investigation was to compare the dimensions of the primary incisors from pre-term children and full-term controls. One hundred and eleven pre-term children, consisting of 86 very-low-birthweight (< 1,500 g), 25 low-birthweight (from 1,500 to 2,500 g), and 169 full-term, normal-birthweight (> 2,500 g) children, donated a total of 572 maxillary and mandibular primary central and lateral incisors for study. The teeth were measured by means of a digital micrometer.

Early experience and validation work with Procedicus VA--the Prosolvia virtual reality shoulder arthroscopy trainer.

Shoulder arthroscopy is a difficult procedure, commonly used for both diagnostic and therapeutic purposes. Until now, the majority of training has been done in theatre, assisting and practising under supervision. Few good simulations exist.

Realtime remote consultation in the outpatient clinic--experience at a teaching hospital.

We used an outpatients' telemedicine clinic to evaluate remote consultation in a London hospital practice. Video-images were relayed by ISDN at 384 kbit/s between the main hospital site and the sister hospital. Teleconsultation was evaluated in three different specialties: pain management, orthopaedics and general surgery.

Sigmoidoscopy in a nurse-practitioner community clinic using telemedicine.

We evaluated the feasibility of remote endoscopy in a community setting. Realtime teleconsultation and telesigmoidoscopy were carried out by a nurse practitioner at a community clinic while a colorectal specialist was present at the main hospital. Rigid video-sigmoidoscopes were used and the images were transmitted via ISDN lines at 384 kbit/s.

Acid-base complex reactions in resin-modified and conventional glass ionomer cements.

Resin-modified glass ionomer cements are a recent development in which the desirable properties of glass ionomer cements and resin-composites are combined. The presence of resin may, however, retard the acid-base reaction of the ionomer component. This has led to a debate regarding the classification of resin modified materials as true glass ionomer cements, and the actual duration of the acid-base reaction after initial setting via light polymerization has taken place.

Undergraduate surgical teaching utilizing telemedicine.

Objectives: To evaluate the concept of a new telemedicine orientated educational application by exposing junior medical students to surgical teaching via video-conferencing from the operating theatre and comparing this to the traditional method currently employed, which requires the presence of students in the operating room. To determine student satisfaction with this novel method and identify deficiencies associated with traditional surgical teaching.

Design: Students were connected by video-conferencing equipment 2 Mbit/s permanent virtual circuits that provided two-way picture and voice communication.

Rigid videosigmoidoscopy vs conventional sigmoidoscopy. A randomized controlled study.

Background: Not only is rigid sigmoidoscopy uncomfortable for patients, but visualisation of the rectosigmoid junction and sigmoid colon is successful in only 40-70% of examinations. A novel fine-bore rigid videosigmoidoscope is described and then compared with a rigid conventional sigmoidoscope for patient discomfort and length of insertion.

Method: A total of 58 patients were examined with both sigmoidoscopes in a random order.

Prevalence of caries in urban Australian aborigines aged 1-3.5 years.

Purpose: This study investigated the prevalence and etiological factors associated with caries in a group of young Australian aboriginal children from 1 to 3.5 years of age.

Methods: One hundred and forty-seven healthy infants, aged from 1 to 3.

The prevalence of pre-eruptive dentin radiolucencies in the permanent dentition.

Purpose: Although intracoronal radiolucencies in radiographs of unerupted teeth have been reported for several decades, the prevalence of this condition remains unknown. This study determined the prevalence and associated dental conditions of permanent teeth showing pre-eruptive dentin radiolucencies in bite-wing radiographs of school children attending two school dental therapy training centers.

Methods: There were 1959 subjects (934 males and 1025 females), each providing a set of bite-wing radiographs which showed the crowns of unerupted permanent teeth.

Preparation of a chitin-apatite composite by in situ precipitation onto porous chitin scaffolds.

Composites of chitin with calcium phosphate were obtained by in situ precipitation of the mineral from a supersaturated solution onto chitin scaffolds. The chitin scaffolds were obtained by freeze drying to give a highly porous structure possessing a polar surface favorable for apatite nucleation and growth. THe extent and arrangement of calcium phosphate deposits on the chitin and substituted chitin scaffolds were explored.

Effects of recycled paper dust extracts on isolated guinea pig trachea.

The effect of paper dust collected at two different locations in a paper recycling plant (PD1 and PD2) on isolated nonsensitized guinea pig tracheal smooth muscle was studied in vitro. Dust extracts were prepared as a 1:10 w/v aqueous solution. Dose-related contractions of guinea pig tracheal rings were elicited with both PD1 and PD2.

Hydroxyapatite modified chitin as potential hard tissue substitute material.

Calcium hydroxyapatite (HA) powder was incorporated into chitin solutions to form an intimate mixture. Upon casting of this mixture into molds of fixed dimensions with subsequent removal of solvent, HAs containing chitin flexible plates were produced. The amount of (HA) was varied from 10 to 50% by mass of HA.

Simultaneous Measurement of Local Gain and Electron Density in X-ray Lasers.

X-ray lasers (XRLs) have experimental average gains that are significantly less than calculated values and a persistently low level of spatial coherence. An XRL has been used both as an injected signal to a short XRL amplifier and as an interferometer beam to measure two-dimensional local gain and density profiles of the XRL plasma with a resolution near 1 micrometer. The measured local gain is in agreement with atomic models but is unexpectedly spatially inhomogeneous.

Promotion of calcification on carboxymethylchitin discs.

A series of water-insoluble carboxymethylchitin (CM-chitin) discs of varying degrees of substitution (d.s.) has been investigated for their interaction with calcium phosphate.

Extreme-ultraviolet interferometry at 15.5 nm using multilayer optics.

The development of multilayer mirror technology capable of operating in the range of 3-30 nm and the construction of thin membranes with excellent uniformity and strength have made it possible to design and implement a Mach-Zehnder interferometer operating at 15.5 nm. We have tested this interferometer by using a soft x-ray laser as a source, and we show its use in probing high-density plasmas.