Sugar loading is not required for phloem sap flow in maize plants

Phloem transport of photoassimilates from leaves to non-photosynthetic organs, such as the root and shoot apices and reproductive organs, is crucial to plant growth and yield. For nearly 90 years, evidence has been generally consistent with the theory of a pressure-flow mechanism of phloem transport. Central to this hypothesis is the loading of osmolytes, principally sugars, into the phloem to generate the osmotic pressure that propels bulk flow. Here we used genetic and light manipulations to test whether sugar import into the phloem is required as the driving force for phloem sap flow. Using carbon-11 radiotracer, we show that a maize sucrose transporter1 (sut1) loss-of-function mutant has severely reduced export of carbon from photosynthetic leaves (only ~4% of the wild type level). Yet, the mutant remarkably maintains phloem pressure at ~100% and sap flow speeds at ~50-75% of those of wild type. Potassium (K⁺) abundance in the phloem was elevated in sut1 mutant leaves. Fluid dynamic modelling supports the conclusion that increased K⁺ loading compensated for decreased sucrose loading to maintain phloem pressure, and thereby maintained phloem transport via the pressure-flow mechanism. Furthermore, these results suggest that sap flow and transport of other phloem-mobile nutrients and signalling molecules could be regulated independently of sugar loading into the phloem, potentially influencing carbon-nutrient homoeostasis and the distribution of signalling molecules in plants encountering different environmental conditions.

Gut Microbiota Regulation of T Cells During Inflammation and Autoimmunity

The intestinal microbiota plays a crucial role in influencing the development of host immunity, and in turn the immune system also acts to regulate the microbiota through intestinal barrier maintenance and immune exclusion. Normally, these interactions are homeostatic, tightly controlled, and organized by both innate and adaptive immune responses. However, a combination of environmental exposures and genetic defects can result in a break in tolerance and intestinal homeostasis. The outcomes of these interactions at the mucosal interface have broad, systemic effects on host immunity and the development of chronic inflammatory or autoimmune disease. The underlying mechanisms and pathways the microbiota can utilize to regulate these diseases are just starting to emerge. Here, we discuss the recent evidence in this area describing the impact of microbiota-immune interactions during inflammation and autoimmunity, with a focus on barrier function and CD4⁺ T cell regulation.

Cholesterol Metabolism by Uncultured Human Gut Bacteria Influences Host Cholesterol Level

The human microbiome encodes extensive metabolic capabilities, but our understanding of the mechanisms linking gut microbes to human metabolism remains limited. Here, we focus on the conversion of cholesterol to the poorly absorbed sterol coprostanol by the gut microbiota to develop a framework for the identification of functional enzymes and microbes. By integrating paired metagenomics and metabolomics data from existing cohorts with biochemical knowledge and experimentation, we predict and validate a group of microbial cholesterol dehydrogenases that contribute to coprostanol formation. These enzymes are encoded by ismA genes in a clade of uncultured microorganisms, which are prevalent in geographically diverse human cohorts. Individuals harboring coprostanol-forming microbes have significantly lower fecal cholesterol levels and lower serum total cholesterol with effects comparable to those attributed to variations in lipid homeostasis genes. Thus, cholesterol metabolism by these microbes may play important roles in reducing intestinal and serum cholesterol concentrations, directly impacting human health.

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Bioinformatics enabled discovery of ismA, a microbial cholesterol dehydrogenase

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Metagenomic species with ismA genes form coprostanol in microbial communities

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ismA+ species are associated with decreased fecal and serum cholesterol in humans

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Effect sizes of ismA+ species on serum cholesterol are on par with human genetics

Engineering chemical interactions in microbial communities

Microbes living within host-associated microbial communities (microbiotas) rely on chemical communication to interact with surrounding organisms. These interactions serve many purposes, from supplying the multicellular host with nutrients to antagonizing invading pathogens, and breakdown of chemical signaling has potentially negative consequences for both the host and microbiota. Efforts to engineer microbes to take part in chemical interactions represent a promising strategy for modulating chemical signaling within these complex communities. In this review, we discuss prominent examples of chemical interactions found within host-associated microbial communities, with an emphasis on the plant-root microbiota and the intestinal microbiota of animals. We then highlight how an understanding of such interactions has guided efforts to engineer microbes to participate in chemical signaling in these habitats. We discuss engineering efforts in the context of chemical interactions that enable host colonization, promote host health, and exclude pathogens. Finally, we describe prominent challenges facing this field and propose new directions for future engineering efforts.

[International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 3. Injuries in the primary dentition. Hebrew edition]

Traumatic injuries to the primary dentition present special problems and the management is often different as compared with the permanent dentition. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialities were included in the task group. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion or majority decision of the task group. Finally, the IADT board members were giving their opinion and approval. The primary goal of these guidelines is to delineate an approach for the immediate or urgent care for management of primary teeth injuries. The IADT cannot and does not guarantee favorable outcomes from strict adherence to the guidelines, but believe that their application can maximize the chances of a positive outcome. The Hebrew Edition is part of the IADT global effort to provide a worldwide accessibility to these guidelines. This third part will discuss injuries in the primary dentition.

[International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Hebrew edition]

Avulsion of permanent teeth is one of the most serious dental injuries, and a prompt and correct emergency management is very important for the prognosis. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the task group. The guidelines represent the current best evidence and practice based on literature research and professionals' opinion. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion or majority decision of the task group. Finally, the IADT board members were giving their opinion and approval. The primary goal of these guidelines is to delineate an approach for the immediate or urgent care of avulsed permanent teeth. The Hebrew Edition is part of the IADT global effort to provide a worldwide accessibility to these guidelines. This scond part of the guidelines will focus on avulsion of permanent teeth.

[International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 1. Fractures and luxations of permanent teeth. Hebrew edition]

Traumatic dental injuries (TDIs) of permanent teeth occur frequently in children and young adults. Crown fractures and luxations are the most commonly occurring of all dental injuries. Proper diagnosis, treatment planning and follow up are important for improving a favorable outcome. Guidelines should assist dentists and patients in decision making and for providing the best care effectively and efficiently. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the group. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the best current evidence based on literature search and professional opinion. The primary goal of these guidelines is to delineate an approach for the immediate or urgent care of TDIs. In this first article, the IADT Guidelines for management of fractures and luxations of permanent teeth will be presented. The Hebrew Edition is part of the IADT global effort to provide accessibility to these guidelines worldwide.

A parallel approach to post source decay MALDI-TOF analysis

We present a novel enhancement to matrix-assisted laser desorption ionization (MALDI) post-source decay (PSD) analysis whereby fragment ions from multiple precursor ions are acquired into the same spectrum without employing a timed ion gate to preselect each parent ion. Fragment ions are matched to their corresponding precursor ions by comparing spectra acquired at slightly different reflectron electric fields. By measuring the difference in time-of-flight (TOF) between the two spectra for each fragment, it is possible to calculate the mass of the fragment ion and its parent. This new "parallel PSD" technique reduces analysis time and consumes less sample than conventional PSD, which requires an ion gate for serial preselection of precursor ions.

Buccal and lingual activity during mastication and swallowing in typical adults

A non-invasive protocol was developed to assess tongue and cheek movements during mastication and to evaluate the temporal relationship between mastication and the initiation of pharyngeal swallowing. Typical adults (three males and three females) were monitored during chewing. Miniature pressure transducers were bonded unilaterally to the buccal and lingual surfaces of the first mandibular molar and the buccal surface of the first maxillary molar on each subject's preferred chewing side. Surface electromyography of the ipsilateral masseter muscle was recorded as an indicator of jaw-closing activity. Pressure and electromyography (EMG) recordings were time-linked to simultaneous B-mode ultrasound imaging of the oral cavity using a submental, coronal view aligned with the first mandibular molar. The intervals between peak pressure recorded at each pressure transducer and peak jaw-closing activity for each masticatory cycle were not statistically different [analysis of variance (anova), P=0.9856] and displayed large statistical variation. These intervals were not different at the beginning of the trials (hard biscuit) than they were at the completion of mastication when the cookie had been broken down to a paste/puree consistency bolus. The interval between the last chewing stroke and the initiation of swallowing was 0.92 +/- 0.34 s). No significant difference existed among subjects for this time interval (anova, P=0.382).

Replantation of avulsed primary incisors: a risk benefit assessment

Parents of preschool children with avulsed primary incisors may request replantation. Although dental textbooks uniformly recommend that primary teeth not be replanted, some case reports advocate the procedure. This review of case reports identifies a number of pathological outcomes of replantation and provides information for clinicians and parents on the risks that may accompany replantation.

Pre-replantation storage of avulsed teeth: fact and fiction

Recent laboratory and clinical studies have proven that there is a rapid decrease in the regenerative potential of normal periodontal ligament the longer an avulsed tooth is out of the socket. These findings make some guidelines for the management of avulsed teeth inaccurate. This paper will review the effects of pre-replantation storage on periodontal ligament healing. In addition, current management recommendations are reviewed and suggestions for change presented.

Comparison of efficacy of ciprofloxacin and doxycycline against experimental melioidosis and glanders

Melioidosis and glanders are caused by the closely related species Burkholderia pseudomallei and Burkholderia mallei, respectively. Whereas melioidosis is a significant cause of morbidity in south-east Asia, glanders is extremely rare. The efficacies of ciprofloxacin and doxycycline were assessed against a strain of B. pseudomallei and a strain of B. mallei which were susceptible to both antimicrobials in vitro. Porton outbred mice and Syrian hamsters were given 40 mg/kg of either doxycycline or ciprofloxacin twice daily by sc injection according to one of three regimens: dosing starting 48 h before challenge and continuing for 5 days postchallenge; 5 days' therapy starting immediately after challenge; 5 days' therapy starting 24 h after challenge. Mice were challenged ip with B. pseudomallei 4845 and hamsters were challenged ip with B. mallei 23344. Antimicrobial efficacy was determined by the shift in the median lethal dose (MLD). Ciprofloxacin prophylaxis and immediate therapy both raised the MLD of B. pseudomallei to 4 x 10(6) cfu from 19 cfu in untreated animals, but therapeutic ciprofloxacin only raised the MLD to 180 cfu. The results for doxycycline were similar. Ciprofloxacin prophylaxis raised the MLD of B. mallei 23344 to 4.6 x 10(5) cfu compared with 4 cfu in untreated controls. Immediate therapy raised the MLD to 7.0 x 10(4) cfu and therapy raised the MLD to 1.6 x 10(3) cfu. All regimens of doxycycline protected hamsters against challenges of up to 2 x 10(7) cfu. Despite using a susceptible strain of B. pseudomallei, neither antimicrobial was effective when used therapeutically. The timely administration of either antimicrobial, however, was effective in preventing symptomatic infection. Doxycycline was the superior of the two antimicrobials against experimental glanders although relapse did occur in treated animals approximately 4-5 weeks after challenge.

Storage conditions of avulsed teeth affect the phenotype of cultured human periodontal ligament cells

After severe injury to the periodontal ligament (PL), the phenotypes of cells recolonizing root surfaces influence the extent and type of repair processes. In teeth that are replanted following avulsion injury, recolonization of the PL space by osteogenic cells instead of by PL fibroblasts may favor bone formation (i.e. ankylosis) instead of PL regeneration. We consider here that recolonization processes depend in part on the storage conditions of the teeth following avulsion. We used an in vitro cell culture model to assess the effect of storage conditions on immunohistochemical staining of several marker proteins that are expressed by osteogenic cells (osteopontin and alkaline phosphatase) and fibroblasts (alpha-smooth muscle actin, type III and XII collagens). Prior to cell culture, extracted human premolar teeth were stored in air ("dry") or in alpha-MEM ("wet") for either 30 or 120 min as surrogate conditions for the variations of extra-alveolar tooth storage that may occur following avulsion. Collagenase/trypsin-digested suspensions of PL cells were prepared from the tissue adherent to the extracted root surface. Passage #2 or #3 cultures were immunostained and examined by fluorescence microscopy. For type XII collagen, cells from wet samples displayed perinuclear staining while cells from 30-min dry samples showed only isolated foci. The staining for 120-min dry samples was weak and non-specific. alpha-Smooth muscle actin was not incorporated into stress fibers in wet samples, whereas dry samples demonstrated prominent stress fibers stained for alpha-smooth muscle actin. Detached cytoplasmic fragments resembling cell processes that stained for alpha-smooth muscle actin were abundant in dry samples, indicating the presence of highly contractile cells. The staining for osteopontin was mainly perinuclear but was more intense in dry samples. The focal adhesion pattern of osteopontin staining in 120-min dry samples resembled that of migrating osteogenic cells. The pattern of staining did not vary for type III collagen or alkaline phosphatase, although staining for alkaline phosphatase was more intense in samples stored under dry conditions. We conclude that prolonged extra-alveolar dry storage favors increased in vitro growth of contractile cells expressing osteogenic cell markers while storage in cell culture medium favors growth of cells with the classical phenotype of PL fibroblasts.

Clinical management of avulsed permanent incisors using Emdogain: initial report of an investigation

The enamel matrix derivative Emdogain was recently approved for clinical use in a number of countries, including Canada. It has been shown to stimulate regeneration of periodontal ligament following periodontal surgery in adults. This paper reviews pertinent clinical and laboratory studies of Emdogain and describes the protocol and methods used for a longitudinal outcome study of replantation of avulsed permanent incisors in children and adolescents. Application of these methods is described in an illustrative case report of Emdogain use. This paper is meant to inform clinicians and guide those who are instituting similar investigations.

In vitro susceptibilities of Burkholderia mallei in comparison to those of other pathogenic Burkholderia spp

The in vitro antimicrobial susceptibilities of isolates of Burkholderia mallei to 16 antibiotics were assessed and compared with the susceptibilities of Burkholderia pseudomallei and Burkholderia cepacia. The antibiotic susceptibility profile of B. mallei resembled that of B. pseudomallei more closely than that of B. cepacia, which corresponds to their similarities in terms of biochemistry, antigenicity, and pathogenicity. Ceftazidime, imipenem, doxycycline, and ciprofloxacin were active against both B. mallei and B. pseudomallei. Gentamicin was active against B. mallei but not against B. pseudomallei. Antibiotics clinically proven to be effective in the treatment of melioidosis may therefore be effective for treating glanders.

The development of ISO 9002 quality management standards for Canadian dental practices

The department of dentistry of the Hospital for Sick Children has actively maintained a quality assurance system since the early 1980s. In addition, members of the department have taught courses and published articles on risk management and quality assurance for over a decade. The decision to achieve ISO 9002 registration led to an intensive 10-month process to adapt ISO systems and standards to Canadian institutional dental practice. This article describes the ISO registration system and the changes required for an existing quality assurance program to conform to ISO standards.

Evaluation of a laser Doppler flowmeter to assess blood flow in human primary incisor teeth

PURPOSE

This study determined whether the portable Advance Laser Flowmeter Model 21, a clinical instrument, would indicate significant values when pulpal blood flow was present or absent; whether the analog output of the flowmeter was time-linked to the heart rate; and whether labial and lingual crown surfaces produced different flow values.

METHODS

Teeth were tested under two conditions: with the teeth in situ and extracted, or with the pulp present and removed.

RESULTS

Values before and after the teeth were extracted, and those before and after pulpectomy with the tooth in situ were significantly different. These findings verified that the flowmeter measured the presence of bloodflow. Peaks of the electrocardiogram waves and the regular signal fluctuations of the flowmeter were time-linked and verified the measurement of the heart rate from the dental pulp. Differences in the values for the lingual and labial surfaces of individual teeth were not significant.

CONCLUSIONS

This instrument proved a valid means of determining the presence of pulpal blood flow in primary incisors.

Interim storage of avulsed permanent teeth

This literature review examines the effects of extra-alveolar duration and storage conditions on the healing of the periodontal ligament (PL) of avulsed teeth following replantation. A critical assessment of the so-called "reconstitution theory" for PL cells is also presented. The ideal treatment for an avulsed tooth is immediate replantation (i.e. less than five minutes). Unfortunately, immediate replantation is not the norm, and most avulsed teeth experience delayed replantation. The greatest risk to the vitality of the PL cells attached to the root of an avulsed tooth is desiccation. Not surprisingly, storage media affect PL healing. Storing avulsed teeth in an isotonic liquid is superior to dry storage. Numerous studies support the use of Modified Eagle's Medium, Hank's Balanced Salt Solution (HBSS), ViaSpan, saline, milk, and saliva as storage media. A recent study has suggested that chicken egg white may also prove to be a suitable storage medium for avulsed teeth. Of these media, only saliva is always present at the scene of an accident, however. Milk can usually be obtained on short notice, but even 10 minutes of desiccation can affect the outcome of replantation. From a practical standpoint, milk packed in ice seems to be the best alternative for the temporary storage of avulsed teeth, due to its wide availability and the minimal detrimental effects it has on PL cells. There is no evidence to support the suggestion that HBSS or any other media will "reconstitute" the PL cells when the extra-alveolar duration of avulsed teeth is greater than 30 minutes.

The influence of storage conditions on the clonogenic capacity of periodontal ligament cells: implications for tooth replantation

Viable periodontal ligament (PL) cells are required for PL healing of avulsed teeth following replantation. If immediate replantation cannot be accomplished, the ability of PL progenitor cells to reproduce (clonogenic capacity) and recolonize the wound may be extended by prevention of desiccation and storage in physiological media. This investigation examined the effects of storage in saliva, milk, Hank's balanced salt solution (HBSS) and Eagle's medium (alpha MEM) on the clonogenic capacity of human PL progenitor cells at 30 and 60 min extra-alveolar time. Twenty erupted human premolar teeth extracted as atraumatically as possible for orthodontic purposes were used in the present study. Fifteen premolars were placed immediately in freshly collected autologous saliva at room temperature, (+ 23 degrees C) for 15 min. These 15 premolars were next divided into three groups of five and stored in either saliva, milk or HBSS at + 4 degrees C in plastic cups surrounded by ice. The remaining five teeth served as positive controls and were immediately placed in alpha MEM at + 4 degrees C. PL tissue was scraped from one-half of the root surface with a scalpel at 30 and 60 min total extra-alveolar duration. Cells were released from the tissue sample with a 30 min enzymatic digestion procedure and the cells from the tissue samples analyzed for clonogenic capacity. There was a reduction in clonogenic capacity with time for all protocols. Periodontal ligament cells stored in alpha MEM showed the least reduction between 30 and 60 min and the greatest reduction was observed for PL cells stored in saliva. The difference in clonogenic capacity following transfer from saliva to milk or HBSS was not significant at 30 min. At 60 min, cells transferred from saliva to HBSS had a statistically higher percentage of clonogenic cells than those transferred to milk (5.9% vs. 3.5%; P < 0.05). We conclude that immediate storage of avulsed teeth in autologous saliva, followed by transfer to chilled milk, preserves the presence of sufficient progenitor cells in the PL to warrant replantation and the possibility of PL healing at 60 min extra-alveolar duration.

Survival of avulsed permanent maxillary incisors in children following delayed replantation

The purpose of this study was to identify the variables that significantly influenced the survival of incisors replanted after extended extra-alveolar duration at The Hospital for Sick Children, Toronto, Canada, between June 1988 and December 1993. Survival analysis was used to identify variables that significantly influence the retention of replanted incisor teeth. Survival was defined as the time that elapsed between the replantation of an avulsed incisor and the time it was finally lost. Information on 9 variables was collected for 38 patients (25 males; 13 females) and 52 replanted permanent maxillary incisors. The mean extra-alveolar duration for the sample was 123 min. The mean follow-up interval was 942 days (range: 364-2126 days). Incisors replanted with open apices had a significantly decreased survival compared with teeth with mature apices (P = 0.04; relative risk 4.2). There was also a significant association between increased survival and obturation of the root canal with gutta-percha and sealer (P = 0.006; relative risk 10.0). A trend towards improved survival of replanted incisors was found for children older than 11 years old at the time of replantation (P = 0.09; relative risk 2.8). These results are consistent with previous studies and may assist clinicians and parents in the decision-making process associated with the management of avulsed teeth in children.

Avulsed permanent teeth: a review of the literature and treatment guidelines

Dental trauma represents one of the few situations where dentists are called upon to make unscheduled diagnostic and treatment decisions in an area that is outside their routine experience. Since patients who sustain an avulsion present infrequently, except in child-oriented or emergency-based practices, clinicians often make diagnostic and management decisions based upon their previous rare treatment experiences. Clinicians also rely on published guidelines for this aspect of their practice and expect these standards to be up-to-date and based on current research information. None of the current protocols has been tested by a prospective longitudinal outcome study in humans. Nevertheless, current guidelines have become the standard for clinical practice around the world. An effort must be made to develop treatment protocols that are based upon the biological mechanisms that underlie periodontal wound healing.

Durational aspects of oral swallow in neurologically normal children and children with cerebral palsy: an ultrasound investigation

Little data exist on the oral management of food boluses in neurologically normal children or children with cerebral palsy (CP). Twenty children with spastic CP and 20 neurologically normal children (age range: 6.2-12.9 years) were monitored with ultrasound imaging of the oral cavity during liquid and solid bolus tasks. A lip-cup contact detector synchronized to ultrasound image output was used during liquid tasks. Data collected from recorded ultrasound images were used to assess durational aspects of the oral phase of swallowing in neurologically normal children and children with CP. Coordinated analysis of ultrasound images with lip-cup contact data allowed timing of intervals in the pre-oral and oral phases of swallowing during liquid feeding tasks. Children with CP required more time than neurologically normal children for collection, preparation, oral transit, and total oral swallow time for 5-ml liquid boluses. Total oral swallow time was longer for solid bolus tasks in children with CP. Oral transit time for solid boluses was significantly longer than for liquid boluses in neurologically normal children and children with CP.

The use of bioelectrical impedance analysis (BIA) to estimate body composition in the Diabetes Control and Complications Trial (DCCT)

Although weight gain often accompanies intensive treatment regimens designed to achieve near-normal glycemia in insulin-dependent diabetes mellitus (IDDM), body composition (BC) has not been well studied. Bioelectrical impedance analysis (BIA) is a safe, rapid, and non-invasive method of assessing BC but has not been utilized widely in IDDM. Data from 46 adults with IDDM were used to develop a regression model estimating fat-free body mass (FFM) from bioimpedance measurements obtained using a proximal electrode placement. Reference values of FFM were determined by dual x-ray absorptiometry (DXA). A model using the ratio of height squared to the minimum resistance of 4 limb-lead combinations (H2/R), total body weight, and a weight-gender interaction achieved a high level of accuracy (R2 = 0.982, residual standard deviation = 1.43 kg), while studies of 10 subjects before and after a light meal found no short-term effect of glycemia on measured BIA variables. BIA will therefore be used in combination with waist-to-hip ratios to study the composition and distribution of the increased weight associated with intensive therapy in the DCCT.

Swallowing/ventilation interactions during oral swallow in normal children and children with cerebral palsy

Many children with cerebral palsy (CP) suffer from feeding disorders. Twenty children with spastic CP and 20 neurologically normal children (age range 6.2-12.9 years) were monitored with ultrasound imaging of the oral cavity synchronized with surface electromyographic (EMG) recordings of masseter and infrahyoid muscles and respiratory inductance plethysmograph (RIP) recordings during feeding tasks. A lip-cup contact detector signaled contact of the drinking cup on the lip during liquid tasks. Children with CP required more time than normals for collection and organization of 5 ml and 75 ml liquid boluses for swallowing. The ventilatory preparation phase, recovery to baseline resting ventilatory pattern after swallowing, and total time for task completion were longer in children with CP for 5-ml and 75-ml tasks. The interval from lip-cup contact until alteration of ventilation from baseline resting ventilatory pattern was longer for children with CP during 75-ml tasks but not for 5-ml tasks. The interval from completion of the task-related cookie swallow until initiation of the next swallow was longer in children with CP than in normal children. These data provide evidence that children with CP manage solid boluses more easily than liquid boluses and small liquid boluses more easily than large liquid boluses. This investigation statistically confirms empirically based recommendations that children with CP be allowed more time to complete feeding tasks and consume small volume drinks rather than large volume drinks.

Design, methods, and conduct of the Optic Neuritis Treatment Trial

The Optic Neuritis Treatment Trial (ONTT) was an investigator-initiated, multi-centered, randomized, controlled clinical trial supported by cooperative agreements and grants. It was designed to evaluate the efficacy and safety of oral prednisone or intravenous methylprednisolone followed by oral prednisone as compared with oral placebo. The primary outcome measures were contrast sensitivity and visual field; secondary measures were visual acuity and color vision. Four hundred fifty-seven patients were followed for a minimum of 6 months and a maximum of 3 years. This article describes the design and the methods used to implement the ONTT.

Ventilation and swallowing interactions of normal children and children with cerebral palsy

The respiratory inductance plethysmograph was used to analyse the ventilatory cycle during drinking, chewing and swallowing of normal and cerebral-palsied children aged between five and 12 years. 33 children were divided equally into three groups: normal, spastic CP and athetoid CP. A few of the children with spastic CP and over half of those with athetoid CP were unable to perform the 'big breath' task. In the remaining trials, the children with CP held their breath for a shorter time than normal children. Many children with CP required multiple swallows to consume 5mL of liquid. In the majority of trials, normal children swallowed liquids at or near the peak of inspiration, whereas the children with CP did not. Supplementary swallows and solid-bolus swallows occurred at any point in the ventilatory cycle in all groups. The children with CP had a greater need to inspire at the end of liquid tasks, especially during the 75mL task.

Quality assurance: a process for continuous improvement

As E.S. Woodlard Jr., Chairman of Du Pont states, "Continuous improvement is vitally important in today's environment. The world is full of savvy, agile competitors who know quality makes a difference." Dentists are part of the health care industry and compete for their patients' discretionary dollars. Careful attention to the development of an integrated RM/QA program for their dental offices is one means of ethical marketing for patient satisfaction. Lessons from the competitive hospitals in the United States and current practices of successful service industries should form part of the framework of the QA component of a practice. A marketing plan is good sense in today's turbulent economic environment and ethical marketing will make the risky "selling" of dental treatment unnecessary.

Risk management: the clinician's defense against liability

As Stock and LeFroy conclude, a RM program lends structure and direction to management. Consistent delivery of high-quality service requires that hundreds of individuals perform numerous roles with a value-added service orientation. Jan Carlzon, the Director of Scandinavian Airlines and the person responsible for its remarkable turnaround, has the proper perspective: "We don't seek to be one thousand percent better at any one thing. We seek to be one percent better at one thousand things." Risk management is one factor in the development of a service-oriented health care culture that leads to sustained profitability through a stable patient base. The development of a RM program for a private dental office will lay the groundwork for a higher goal; a demonstrable, verifiable quality of care throughout the practice.

Composite resin short-post technique for primary anterior teeth

A technique using a "mushroom shaped" composite resin short post constructed inside the pulp-treated root canal provides sufficient retention to build a composite resin crown on the reinforced superstructure of the remaining crown dentin. This technique was tested for 1 year in 92 teeth; they showed no failures of retention of the short post. Recurrent caries and severe bruxism--factors beyond operator control--posed some problems that were readily resolved.

Correlation of ultrasound imaging of oral swallow with ventilatory alterations in cerebral palsied and normal children: preliminary observations

Preliminary results of an investigation that synchronizes the videotaped output of ultrasound camera and the analog data from physiological measurements of swallowing and ventilation in normal and cerebral palsied (CP) children are presented. Four cerebral palsied children and three control children undertook a single sip-swallow of 5 ml of liquid and a solid mastication-swallow sequence on three occasions according to a defined protocol. The CP children exhibited much more variability and less control of the liquid bolus than did the controls. The ultrasound image clearly demonstrates the lack of control of the posterior of the tongue in many CP children. Some parts of the sequence of oral swallow and the time to achieve maximum anterior displacement of the hyoid bone appear to be slowed. The sequential events of swallowing show less variability as the sip-swallow proceeds from the oral voluntary to pharyngeal and lower involuntary phases. This study also identified a short-latency apnea that appears to accompany a saliva (protective) swallow and a long-latency apnea that accompanies semi-solid or liquid bolus (alimentary) swallows. Further investigations of normal and CP children utilizing a combined diagnostic imaging-physiological measurement approach will follow this initial study.

'Locked-in' syndrome. Occurrence after coronary artery bypass graft surgery

The 'locked-in' syndrome has not previously been described in the immediate period after open-heart surgery. We describe the case of a patient who remained tetraplegic and mute, but alert, after graft surgery. A brief review of the aetiological factors in the development of this type of stroke after coronary artery bypass is presented.

Growth, development, and aging of orofacial tissues: neural aspects

Neural factors influence post-natal growth, development, and aging throughout the body. This influence may be mediated through sensory or motor effects interacting with endocrine and immunological factors. Growth effects may be expressed directly by sensory or motor nerves on the tissue or indirectly by motor function. Direct neutrotrophic effects have been well-documented in the development of striated muscle, the taste bud, and the amphibian limb. Evidence for a trigeminal neurotrophic effect on tooth development and facial development is lacking. Growth disturbances of the jaws consequent to lesioning of the trigeminal nerve are due most likely to functional disturbances rather than neutrotrophism. Examples of function impact on orofacial growth are abundant. Oral and facial target tissues, like those elsewhere in the body, determine the nature of the target tissue innervation and its central organization. Central effects consequent to tooth loss or dental pulp entirpation are well-documented. Inflammation and pain may exert growth effects through release of "wound hormones" or secondarily to somatic and autonomic effects. There is evidence that vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP) elaborated from sympathetic and parasympathetic neurons may have a modulatory role in growth. While the effects of longstanding motor pathologies on skeletal growth are well-known, concomitant sensory deficits and soft tissue disturbances have not been examined. However, the pathological models beg the question of normal regulation. While muscle develops in the absence of innervation, neurotrophic effects are clearly identified. Little is known about the interaction of simple and complex motor behavior on growth. Regulation of growth is frequently visualized within a form-function paradigm. For example, anterior open bites have been seen as the consequence of tongue thrusting or tongue thrusting as a consequence of open bites. Low tonic forces in posture are thought to be more important in the development of both the face and the dental alveolar complex than the higher intermittent forces in mastication and swallowing. The need for an active (reflex) contribution to growth at the TMJ is in dispute.(ABSTRACT TRUNCATED AT 400 WORDS)

The multidisciplinary feeding profile: a statistically based protocol for assessment of dependent feeders

The development of the multidisciplinary feeding profile entailed a level of statistical analyses not commonly utilized in test development. This paper describes the statistical analyses and offers an explanation of why specific statistical tests were chosen. It also serves to identify where clinical knowledge and experience overrode specific statistical tests.

Development of a multidisciplinary feeding profile for children who are dependent feeders

The multidisciplinary feeding profile (MFP) is the first statistically based protocol for the quantitative assessment of feeding disorders in severely disabled children. This assessment can be completed in 30-45 min with foods and facilities that are available in homes, hospitals, and chronic care units. This paper describes the state of current testing methods, the parameters of successful feeding activity, the development of the test protocol, and the results of statistical analyses.

Ear lobe crease and coronary artery disease in patients undergoing coronary arteriography

An association between the ear lobe crease and coronary heart disease has been documented. A prospective study of 125 consecutive patients undergoing coronary arteriography was carried out to evaluate the ear lobe crease with the presence and extent of coronary artery disease. An ear lobe crease was observed in 65 patients, but this trait was not related to age, sex, smoking history, previous myocardial infarction, history of hypertension, family history of heart disease, body mass index or angiographically defined coronary artery disease. We conclude the ear lobe crease is not related to coronary heart disease.

Feeding disorders research and teams: a new challenge for dentistry

Feeding disorders, which include masticatory and cerebral disabilities, present a major problem for disabled persons, but only in the last decade have health professionals shown an increased interest in the diagnosis and management of patients with such problems. Dentists are experts in the diagnosis and treatment of disorders of the oral-facial region, yet they have either worked in intradisciplinary isolation or have not demonstrated their interest in patients with feeding disorders. Consequently, those involved in the assessment and treatment of persons with feeding disorders are not aware of the contributions dentists have made to the basic and clinical data base of feeding assessment and therapy. Dentistry is simply not mentioned in rehabilitation. The opportunity now exists for dentistry to inform others of our expertise in the field from both a research and a clinical perspective. The basic and clinical base of dental therapeutics and its role in the diagnosis and treatment of disorders of the masticatory apparatus and of swallowing are reviewed here. It is hoped that this review will stimulate interest among dentists to take part in the rehabilitation of patients with feeding disorders through the use of the extensive data base within the profession.

Biofeedback techniques and behaviour modification in the conservative remediation of drooling by children with cerebral palsy

In an attempt to decrease the rates of drooling of 12 children with cerebral palsy, the authors investigated the effectiveness of EMG auditory feedback training of the orbicularis oris, of making the act of swallowing a conscious one, and of providing an auditory signal to cue swallowing by means of an Accularm interval timer. After biofeedback training there was a significant decrease in drooling rates and a small increase in swallowing rates. After the Accularm was used the children maintained the decreased drooling rates and there was a further small improvement in swallowing rates. One month after treatment stopped there was a non-significant regression in the rates of both drooling and swallowing. The marked decrease in drooling after biofeedback training must be attributed to more effective swallowing as a result of improved oral motor control, rather than to increased rates of swallowing.