Formation of formate and hydrogen, and flux of reducing equivalents and carbon in Ruminococcus flavefaciens FD-1.

A pathway for conversion of the metabolic intermediate phosphoenolpyruvate (PEP) and the formation of acetate, succinate, formate, and H2 in the anaerobic cellulolytic bacterium Ruminococcus flavefaciens FD-1 was constructed on the basis of enzyme activities detected in extracts of cells grown in cellulose- or cellobiose-limited continuous culture. PEP was converted to acetate and CO2 (via pyruvate kinase, pyruvate dehydrogenase, and acetate kinase) or carboxylated to form succinate (via PEP carboxykinase, malate dehydrogenase, fumarase, and fumarate reductase). Lactate was not formed even during rapid growth (batch culture, mu = 0.

Pessimistic attributional style: is it specific to depression versus anxiety versus negative affect?

Two studies with college students explored the relationship of a pessimistic attributional style to positive and negative affect, as well as to depressed and anxious mood. Both studies revealed that a pessimistic attributional style was correlated with negative affect and depressed mood, but was unrelated to low levels of positive affect. The second study also showed a correlation with anxiety and that the association of pessimistic attributional style with emotional distress occurs for both depression-relevant (i.

Abnormal lignin in a loblolly pine mutant.

Novel lignin is formed in a mutant loblolly pine (Pinus taeda L.) severely depleted in cinnamyl alcohol dehydrogenase (E.C.

Bovine cumulus cell expansion does not depend on the presence of an oocyte secreted factor.

Communication between the oocyte and its somatic cells has been shown to be important in oocyte development. Here we examined how the oocyte may be involved in bovine cumulus cell expansion. Intact bovine cumulus oocyte complexes (COC) were obtained by puncturing antral follicles.

Consultant services in restorative dentistry.

Since restorative dentistry was established as a specialty in the UK in 1973, consultant appointments in the field have largely centred around the dental teaching hospitals with a considerable shortage of posts in the district general hospitals. This article explains the growing demand for restorative consultants and calls for the expansion of the hospital restorative dental service.

An in vitro assessment of tooth preparation for porcelain veneer restorations.

Objectives: This in vitro study aimed to examine the depth of preparation and incidence of dentine exposure resulting from the use of a 'freehand' technique to prepare maxillary central incisors for porcelain veneers.

Methods: Twenty-two maxillary central incisors were selected. Prior to preparation an index of the labial surface of each tooth was recorded and the tooth secured in a jig to permit accurate relocation.

Problems in restorative dentistry: who copes with them?

The views of general dental practitioners, practising in part of the Yorkshire Region, as to how they would cope with a variety of restorative problems were sought using a questionnaire. If advice or advice and treatment were to be requested from a consultant in restorative dentistry, the questionnaire was designed to discover whether the distance from a hospital created a barrier to the preferred course of action. Only one-third of the dentists were happy to treat a troublesome complete denture case, provide a replacement obturator or look after a natural dentition with considerable periodontal problems.

Obsessive-compulsive symptoms and the family.

A questionnaire study of 98 family members of individuals with obsessive-compulsive symptoms revealed that 60% of the family members were involved to some extent in rituals with the affected family member. Nearly all family members reported at least some degree of interference in their lives. Information was also gathered about the sort of rituals in which members were involved, how they responded to the demands of the affected relative to engage in the rituals, their beliefs and knowledge about compliance, and the degree to which the rituals interfered in their lives.

The influence on partial denture design of a teaching video for general dental practitioners.

This evaluation was based on replies from a random sample of general dental practitioners who were asked to complete questionnaires before and after being sent a video and accompanying booklet on partial denture design. Forty per cent (257) of the original sample (636) completed and returned both questionnaires. A total of 212 respondents (82%) felt the video had been of value and 175 (68%) said they would be more likely to provide metal partial dentures after having watched it.

Hardiness, stress, and burnout among intensive care nurses.

The purposes of this study were to determine whether hardiness is a predictor of burnout and whether it can buffer the effect of stress on burnout. Thirty-one registered nurses who work in intensive care units completed the Hardiness test, the Nursing Stress scale, and the Tedium scale. Descriptive statistics, correlational statistics, t tests, analysis of variance, and hierarchical multiple regressions were used to analyze the data.

Complete denture prescription--an audit of performance.

The quality of clinical records obtained during the various stages of complete denture construction was assessed in a survey conducted in five large dental laboratories in 1989. The most common fault in approximately half of 188 upper and 158 lower impressions was overextension in the labial and buccal sulci. Of the 87 occlusal records examined, the rims indicated the intended incisal relationship in about 50% of cases.

Synthesis and spectroscopic characterization of hydroxycinnamoylated methyl alpha-L-arabinofuranosyl-(1-->2)- and (1-->3)-beta-D-xylopyranosides.

A reaction sequence for the preparation of methyl 5-O-feruloyl-alpha-L- arabinofuranosyl-(1-->3)-beta-D-xylopyranoside, the companion 5-O-p-coumaroyl disaccharide, and their (1-->2) analogs has been developed. The (1-->3) hydroxycinnamoylated disaccharides are available in 11 steps from L-arabinose and methyl beta-D-xylopyranoside in 17% overall yield (based on methyl beta-D-xylopyranoside). The corresponding (1-->2) materials were prepared in 9 steps in > 37% overall yield.

Synthesis of methyl 5-O-trans-feruloyl-alpha-L-arabinofuranoside and its use as a substrate to assess feruloyl esterase activity.

A synthetic scheme was developed for the production of methyl 5-O-trans-feruloyl-alpha-L-arabinofuranoside (FA-Ara) in gram quantities. This molecule accurately models the chemical attachment of ferulic acid to polysaccharides found in cell walls of plants in the Gramineae family. It is therefore a realistic substrate that can be used to monitor feruloyl esterase activity.

Enhancing the coping skills of mothers with developmentally delayed children.

Recent studies have shown that mothers of developmentally delayed children are at risk for depression. During weekly psychoeducational group meetings, Roy's adaptation model was used to identify the focal, contextual, and residual stimuli that contributed to the mothers' depression. Nursing interventions that encouraged adaptation in the four modes were implemented by group facilitators providing parent education and emotional support.

Synthesis of affinity ligands and radioactive probes for isolation and study of myo-inositol 1,4,5-trisphosphate binding proteins.

To synthesize an affinity matrix for isolation of D-myo-inositol 1,4,5-trisphosphate binding proteins, racemic 3-cyclohexene-1-carboxaldehyde was oxidized and converted to a mixture of trans-3,4-di-hydroxycyclohexane-1-carboxylic acid methyl ester isomers, which was phosphorylated and separated into (+-)-(1R,3R,4R)- and (+-)-(1R,3S,4S)-trans-3,4-bis[(diphenoxyphosphoryl)oxy]cyclohex an e-1- carboxylic acid methyl esters. Each of these racemic compounds was hydrogenolyzed and reacted with ethylenediamine to give a monoamide, N-(2-aminoethyl)-bis(phosphonyloxy)cyclohexane-1-carboxamide, that was coupled to cyanogen bromide activated Sepharose 4B to provide the desired affinity matrices. The intermediate trans-3,4-bis[(diphenoxyphosphoryl)oxy]cyclohexane-1-carboxylic acid methyl ester was also reduced with lithium borotritide to give the (hydroxy[3H]methyl)cyclohexane derivative, which was phosphorylated and hydrogenolyzed to yield trans-3,4-bis(phosphonyloxy)-1-[(phosphonyloxy)[3H]methyl]cy clohexane, a radiolabeled analogue of inositol 1,4,5-trisphosphate.

American education: the challenge of change.

The American education system is being challenged to raise the academic achievement of students to prepare them for the jobs of the future. Yet many demographic, as well as economic and social factors, are making the task more difficult. Low birth rates, especially among non-Hispanic whites, along with high immigration rates, have increased the share of minority and non-English students in public schools.

The role of overdentures in gerodontics.

As more people keep their teeth later in life, more and more patients in the future will still be partially dentate at an age when, previously, the edentulous state was the norm. The overdenture has a part to play in restorative dentistry for these patients. It can be a relatively simple, inexpensive prosthesis; but, like so many other aspects of dentistry, will provide long-term success only if the patient and the mouth have been assessed with care and a rigorous after-care programme instituted.

Morphological alterations in cultured neuromuscular tissue induced by two anesthetic agents.

A diversity of pathogenic effects was observed in two complementary culture systems following their exposure to the anesthetic agents. Thiopental sodium and ketamine hydrochloride. The cytotoxic effects of both agents in these two culture types were reversible and dose-related.

Retention of glucose in oral fluid at different sites in the mouth.

Using glucose as a marker, a detailed study of retention at 5 different sites in the mouth of 1 subject and a less detailed examination of 4 selected sites in the mouths of 10 other subjects revealed site-specific differential patterns of oral retention (or clearance). These patterns seemed independent of sometimes large, absolute day-to-day variations in oral retention which occur in all subjects but appeared to vary somewhat between subjects, probably reflecting slight differences in the anatomy and physiology of the individual mouth. In general, the patterns resembled those recently derived from studies of other oral phenomena such as rates of diffusion out of plaque, fluoride uptake by mineral and hydrogen ion concentrations in plaque.

Availability of fluoride at different sites in the buccal sulcus.

After rinsing with a fluoride solution, the amounts of fluoride taken up by small pieces of dentine placed strategically about the mouth varied considerably from site to site in the oral cavity. The pattern of fluoride availability in this subject's mouth was in line with previous findings about fluoride distribution in his labial sulcus. The present results therefore suggest by analogy that considerable variations in fluoride clearance and concentration must exist throughout the oral cavity.

The budget of lead, copper and cadmium for a major highway.

Data on deposition fluxes and concentrations of lead, cadmium and copper in road drainage water at proximate sites on the M6 motorway in northwest England have been analysed. The integration of fluxes over a year indicates that metal removal in road drainage water exceeds that deposited on the roadside verges, most markedly in the case of copper. From estimates of the source strength for lead, it is concluded that approximately 90% of emissions are dispersed by the atmosphere away from the immediate vicinity of the road.