Accidental Ingestion of an Implant Screwdriver: A Case Report and Literature Review.

Head and neck oncology patients are high risk for ingestion or aspiration of dental instruments during treatment, due to altered anatomy and sensation. This article describes a case report of accidental ingestion of an implant screwdriver during the prosthetic phase of oral rehabilitation of a 79 year old oncology patient. The management protocol is described which included referral to the medical Accident and Emergency department, where the object was safely removed from the stomach via endoscopy. A review of similar cases of ingestion/inhalation in the literature suggests implant screwdrivers should be retrieved as safe passage through the gastrointestinal system is not assured. Awareness of the medical history and risk factors should alert clinicians to be extra cautious, and preventative strategies should be implemented at all times. Preventative measures include ligation of instruments with floss/suture material, treatment in a more vertical position, and use of rubber dam where possible.

A Randomised Controlled Trial of Postoperative Sensitivity after Class II Restoration with Bulk-Fill vs Conventional Composites.

INTRODUCTION: Bulk-fill composites may simplify posterior restorations, saving time and reducing technical complexity. Post-operative sensitivity is a risk of posterior composites; bulk-fill composites could mitigate this. This single centre, double-blinded, parallel groups randomised controlled trial compared postoperative sensitivity following restoration of class II carious lesions with bulk-fill or conventional, layered composite. NULL HYPOTHESIS: there will be no difference in post-operative sensitivity between the two materials. METHODS: Participants requiring class II restoration of posterior teeth were randomised to bulk-fill (FU) (Coltene Fill-UpTM) or conventional, layered (BE) (Coltene Brilliant Everglow) composite. Allocation was concealed during cavity preparation. Only the operating dentist knew allocation. The outcome was 24 h post-operative sensitivity. RESULTS: 41 patients were randomised (20/group). Two patients from FU group were excluded from analysis (factors unrelated to intervention). There was no difference in postoperative sensitivity at 24 h nor any time point. Only participant age and baseline sensitivity scores significantly impacted post-operative sensitivity. One restoration debonded in FU group at 10 days, with no other adverse effects. No difference in time taken to place restorations was seen. CONCLUSIONS: Within the study's limitations, post-operative sensitivity after class II posterior restorations was no different in bulk-fill restorations compared with conventional, incrementally cured composite.

Implementation of an international barcode labeling standard, International Society of Blood Transfusion 128, and its integration with local regulations at a blood center in India: Step-by-step journey.

The International Society of Blood Transfusion (ISBT) 128 is an internationally endorsed, electronically readable labeling standard that provides a convenient and accurate means of identification, traceability, publication, and storage of information for blood and blood products. The authors' center recently registered with the International Council for Commonality in Blood Banking Automation (ICCBBA) and progressed to ISBT 128 labeling standard. This manuscript was written with the objective of sharing the authors' experience with respect to the implementation of ISBT 128 standards for whole blood donations and integration of ISBT 128 standards with Indian licensing regulations. The authors explore the process of implementation of ISBT 128 standards through a step-by-step journey that included facility registration with International Council for Commonality in Blood Banking Automation (ICCBBA), allotment of facility identification number, development of four-quadrant label for blood components, and integration of local regulatory requirements in the final "composite" label. Acknowledging the lack of any published report from India on ISBT 128 standards implementation, the authors wish to attempt help their peers in understanding and implementation of this global standard at their respective facilities.

Pre-hospital ECPR in an Australian metropolitan setting: a single-arm feasibility assessment-The CPR, pre-hospital ECPR and early reperfusion (CHEER3) study.

INTRODUCTION: Survival from refractory out of hospital cardiac arrest (OHCA) without timely return of spontaneous circulation (ROSC) utilising conventional advanced cardiac life support (ACLS) therapies is dismal. CHEER3 was a safety and feasibility study of pre-hospital deployed extracorporeal membrane oxygenation (ECMO) during cardiopulmonary resuscitation (ECPR) for refractory OHCA in metropolitan Australia. METHODS: This was a single jurisdiction, single-arm feasibility study. Physicians, with pre-existing ECMO expertise, responded to witnessed OHCA, age < 65 yrs, within 30 min driving-time, using an ECMO equipped rapid response vehicle. If pre-hospital ECPR was undertaken, patients were transported to hospital for investigations and therapies including emergent coronary catheterisation, and standard intensive care (ICU) therapy until either cardiac and neurological recovery or palliation occurred. Analyses were descriptive. RESULTS: From February 2020 to May 2023, over 117 days, the team responded to 709 "potential cardiac arrest" emergency calls. 358 were confirmed OHCA. Time from emergency call to scene arrival was 27 min (15-37 min). 10 patients fulfilled the pre-defined inclusion criteria and all were successfully cannulated on scene. Time from emergency call to ECMO initiation was 50 min (35-62 min). Time from decision to ECMO support was 16 min (11-26 min). CPR duration was 46 min (32-62 min). All 10 patients were transferred to hospital for investigations and therapy. 4 patients (40%) survived to hospital discharge neurologically intact (CPC 1/2). CONCLUSION: Pre-hospital ECPR was feasible, using an experienced ECMO team from a single-centre. Overall survival was promising in this highly selected group. Further prospective studies are now warranted.

Implant-supported oral rehabilitation in oncology patients: a retrospective cohort study.

Oral rehabilitation after treatment for head and neck cancer can be challenging. Implant-supported rehabilitation can considerably improve oral health-related quality of life, but there is a dearth of contemporary evidence of reported outcomes and trends in this cohort. In this study we retrospectively investigated the outcomes of 115 patients (376 dental implants) with a mean (range) follow up of 3.91(0.11-12.76) years. We considered survival of the implants, percentage of those used for prosthetic rehabilitation, time from diagnosis to placement and restoration, additional operations involving soft-tissue revision, and the effects of radiotherapy, chemotherapy, and reconstructive flaps on these outcomes. Implant survival was 97%. A total of 32% of patients had radiotherapy with a mean dose of 61Gy. A total of 94% of cases were restored with all the implants placed. Computed coefficients from a multinomial logistic regression model suggested that a trend towards radiotherapy, implant placement in the graft, and placement in the maxilla had a negative influence on success, but this was not significant (p>0.05). The placement of implants in a reconstructive flap was strongly associated with the need for soft tissue revision. The approach used (placement during primary cancer resection or after) significantly influenced the time to placement and restoration (p=0.016). These data suggest a local trend towards earlier placement of implants (during primary cancer resection) resulting in earlier restorative rehabilitation. Outcome data show that the survival of implants is comparable to that in non-oncological cases, and that radiotherapy and location of the implant have less influence on implant survival than previous studies have suggested.

Treatment of sialorrhoea with repeated ultrasound-guided injections of botulinum toxin A into the parotid and submandibular glands.

Botulinum toxin injections are useful in patients with refractory sialorrhoea although the optimum treatment protocol and its efficacy over a long period of follow up are controversial. The aim of our prospective study was to examine the efficacy and complications of a protocol of repeated ultrasound-guided botulinum toxin injections of fixed doses at a tertiary children's hospital. A total of 79 procedures were done in 34 patients who were followed up for two years. The overall complication rate was 3%. The outcome measures considered included the Drooling Frequency Severity Scale (DFSS), visual analogue scale (VAS), and carers' assessments of the reduction in drooling. Our study highlighted two types on non-responders (primary and secondary) of which 3/34 required definitive surgical management. In summary, this study shows that a protocol of repeated injections of fixed doses of botulinum toxin A, while not beneficial in all cases, is a potentially valuable option for the safe and effective treatment of sialorrhoea in children.

Conservative aesthetic techniques for discoloured teeth: 2. Micro-abrasion and composite.

The first article in this series discussed the minimal intervention approach to discoloured teeth, starting with dental bleaching. This second article goes on to explain the technique of microabrasion and the use of direct composite techniques.

Conservative aesthetic techniques for discoloured teeth: 1. The use of bleaching.

There is an increasing move towards more minimally invasive techniques in restorative dentistry. This series of two articles discusses conservative techniques for the treatment of discoloured teeth. A step-wise approach to treatment is promoted to encourage the most conservative solution to achieve satisfactory aesthetics. The first of these two articles will describe the use of bleaching, whilst part two will go on to describe microabrasion and the use of direct composite resin.

Regenerative endodontic therapy for managing immature non-vital teeth: a national survey of UK paediatric dental specialists and trainees.

Background Several guidelines have been published advocating the use of regenerative endodontic therapy (RET) in managing non-vital immature permanent teeth. It is unclear, however, how many UK paediatric dental specialists routinely use this technique and their opinion of its outcomes, and barriers to its use.Aim To assess the knowledge, experience and the opinion of UK based paediatric dental specialists/trainees (UKPDS/T) and practitioners working in the capacity of paediatric dental specialists on the use of RET.Design A cross-sectional study using a 22-item questionnaire was developed using the Bristol Online Survey tool and circulated electronically to members of the British Society of Paediatric Dentistry between August and November 2016.Results Ninety-eight UKPDS/T completed the survey. A quarter of respondents (N = 24, 24.5%) reported using RET. Reasons cited for not using RET included lack of: training (N = 48, 45%), materials (N = 28, 26%), evidence (N = 17, 16%) and suitable cases (N = 6, 6%). Different protocols in terms of disinfection, medicaments, scaffolds, and obturation material were identified.Conclusions This survey highlights a low uptake of RET by current UKPDS and trainees with several barriers identified. Deviations from the current RET guidelines were identified. Recommendations addressing the use of RET in light of the findings of this survey were made.

Impaired utilization of serum folate in pernicious anemia. A study with radiolabeled 5-methyltetrahydrofolate.

The possible role of cobalamins in the utilization of serum methyltetrahydrofolate has been investigated by means of radiolabeled methyltetrahydrofolate in subjects suffering from pernicious anemia. After intravenous administration, methyltetrahydrofolate-(3)H (SA 11,500 Ci/mole; dose 0.05 mug/kg) was cleared from the serum to tissues of B(12)-deficient subjects half as fast as after the same subjects had received vitamin B(12) therapy. B(12) deficiency was also associated with an increased rate of renal excretion of methyltetrahydrofolate or its derivatives, and a decreased rate of renal metabolism of methyltetrahydrofolate to other urinary folate derivatives.Intravenously administered methyl-(14)C-tetrahydrofolate-(3)H at a higher dose (5 mug/kg) caused a severalfold elevation of the total serum folate concentration and, in B(12)-deficient subjects, it did not disappear from the serum significantly more slowly although its urinary excretion was significantly increased. These results indicate that there is some cobalamin requirement for the utilization of serum methyltetrahydrofolate and verify one prediction of the "methyltetrahydrofolate trap" explanation for the megaloblastosis of B(12) deficiency.

Transport characteristics of folates in cerebrospinal fluid; a study utilizing doubly labeled 5-methyltetrahydrofolate and 5-formyltetrahydrofolate.

Serum disappearance curves in dogs after the intravenous injection of radioactive methotrexate, 5-methyltetrahydrofolate, 5-formyltetrahydrofolate, and folic acid followed first-order kinetics with half-disappearance times ranging from 1.3 to 9 hr respectively. Equilibration of spinal fluid tritium levels with those in serum was rapid (3.0 hr) for both of the reduced folates but was not observed at any time after folic acid and methotrexate. The only radioactive folate identified in the spinal fluid after intravenous injection of either 5-formyltetrahydrofolate or folic acid, as well as 5-methyltetrahydrofolate was 5-methyltetrahydrofolate. These findings indicated that 5-methyltetrahydrofolate was taken up preferentially into the spinal fluid and that the other folate congeners were converted to this compound before uptake. Diphenylhydantoin administration did not alter the uptake of 5-methyltetrahydrofolate into the spinal fluid but was associated with reduced renal excretion of this compound.

Intestinal folate absorption. I. 5-Methyltetrahydrofolic acid.

Intestinal absorption of the monoglutamate form of the principal dietary and circulating folate compound, 5-methyltetrahydrofolic acid (5-MTHF), was studied in the rat utilizing a synthetic highly purified radiolabeled diastereoisomer. Chromatography confirmed that the compound was not altered after transfer from the mucosa to the serosa. Accumulation against a concentration gradient was not observed in duodenal, jejunal, or ileal segments at 5-MTHF concentration from 0.5 to 500 nmoles/liter. Unidirectional transmural flux determination also did not indicate a significant net flux. Mucosal to serosal transfer of 5-MTHF was similar in all segments of the intestine and increased in a linear fashion with increased initial mucosal concentrations. Further, no alteration in 5-MTHF transfer was found when studied in the presence of metabolic inhibitors or folate compounds. These results indicate that 5-MTHF is not absorbed by the rat small intestine by a carrier-mediated system and suggest that 5-MTHF transfer most likely represents diffusion.

Bulk-fill resin-based composite restorative materials: a review.

Resin-based composite (RBC) materials are increasingly being used for the restoration of posterior teeth. The increasing demand for aesthetic, tooth-coloured restorations coupled with the patient's concerns regarding the use of mercury containing restorations, has driven a surge in the use of RBC materials. With the Minamata Convention in 2013 calling for the phase-out of dental amalgam and dental schools increasingly teaching techniques for RBC restorations in posterior teeth, it is likely that the dental profession's reliance upon RBC for the restoration of posterior teeth will only increase. In order to simplify and speed-up the placement of large posterior RBCs, manufacturers have produced a range of materials which can be placed in single or deeper increments, known as bulk-fill RBCs. Over a relatively short period of time many bulk-fill RBCs have been marketed quoting increment depths between 4-10 mm. The placement of these larger increments of RBC may reduce the time needed when placing posterior restorations and thereby reduce technique sensitivity. This article aims to review the properties and handling characteristics of the bulk-fill RBC materials currently available, while advising the optimal techniques of placement.

Nucleotide sequence of the psbE, psbF and trnM genes from the chloroplast genome of Chlamydomonas reinhardtii.

We have determined the nucleotide sequences of the psbE and psbF genes, which encode the alpha and beta subunits, respectively, of cytochrome b-559, from the chloroplast genome of the green alga Chlamydomonas reinhardtii. In contrast to other organisms psbE is not co-transcribed with psbF. The primary structures of the gene products are very similar to the equivalent proteins in cyanobacteria and plants. Each subunit contains a single histidine residue that is thought to ligate haem. Upstream of the psbE gene, a trnM gene is located which encodes an elongator tRNA(Met) molecule.

Nucleotide sequence of the petB gene encoding cytochrome b6 from the mesophilic cyanobacterium Synechocystis PCC 6803: implications for evolution and function.

The gene encoding the cytochrome b6 subunit (petB) of the cytochrome b6f complex has been isolated, cloned and sequenced by nonradioactive methods from genomic DNA of the unicellular cyanobacterium Synechocystis sp. PCC 6803. The coding region consists of 666 nucleotides, coding for a polypeptide with a molecular mass of 25.02 kDa. In contrast to higher plant petB sequences an aminoterminal extension of seven amino acids occurs. Aminoterminal sequencing of the isolated protein excludes--different from higher plants--the existence of an intron after the first amino acids but indicate the posttranslational removal of three amino acids from the amino terminus. The aminoterminal extension--found only in non-nitrogen-fixing, unicellular cyanobacteria--shows a high degree of homology between different species.

An inverse relationship of rat liver folate polyglutamate chain length to nutritional folate sufficiency.

The relative concentrations of folylpolyglutamates of differing chain length in rat liver and the uptake of exogenous [3H]folic acid (20 microCi, 20 microgram) into liver folylpolyglutamates were examined in rats maintained on (a) standard and folate-supplemented standard diets and (b) semi-defined folate-sufficient and folate-deficient diets. Folylpolyglutamates extracted from liver were cleaved to p-aminobenzoylpolyglutamates which were separated by ion-exchange chromatography. The relative concentrations and ultimate radiolabeling of longer-chain folylpolyglutamates (six, seven and eight glutamate residues) were greatest in the livers of folate-deficient rats, whereas the intermediate-chain folylpolyglutamates (three, four and five glutamate residues) were the greatest portion of total liver folates of folate-supplemented rats. Thus, the length of the polyglutamate chain added to liver folates is inversely related to the total concentration of liver folates. These data suggest that folylpolyglutamate biosynthesis in the liver may be controlled by the liver folate concentrations. In folate insufficiency such a control mechanism would serve to enhance the affinity of folates for folate-dependent enzymes and to conserve the liver folate concentration.

Folates of rat tissue. Bioassay of tissue folylpolyglutamates and a relationship of liver folypolyglutamates to nutritional folate sufficiency.

The folate content of young rat tissues extracted into boiling ascorbate was assayed by Lactobactillus casei both without and after treatment by a folate-free preparation of conjugase. The total folate content of various tissues was: liver, 8.9 microgram/g; kidney, 2.6; adrenal, 2.6; bone marrow, 2.4; spleen, 0.9; erythrocytes, 0.8; small intestinal mucosa, 0.7; small intestinal smooth muscle, 0.8; heart, 0.6; brain, 0.4, and skeletal muscle, 0.1 microgram/g tissue. For most tissues, with the exception of muscle and kidney, approximately 80% of the total folates assayed as longer chain length folylpolyglutamates. When liver folates were analyzed from rats fed folate-supplemented, control and folate-deficient diets, a relationship was found between folate nutrition and distribution of folylpolyglutamates. The proportion of total folates in the form of longer chain length folylpolyglutamates was greatest in the livers of folate-deficient rats and least in the livers of folate-supplemented rats.

Energetics of a strongly pH dependent RNA tertiary structure in a frameshifting pseudoknot.

Retroviruses employ -1 translational frameshifting to regulate the relative concentrations of structural and non-structural proteins critical to the viral life cycle. The 1.6 A crystal structure of the -1 frameshifting pseudoknot from beet western yellows virus reveals, in addition to Watson-Crick base-pairing, many loop-stem RNA tertiary structural interactions and a bound Na(+). Investigation of the thermodynamics of unfolding of the beet western yellows virus pseudoknot reveals strongly pH-dependent loop-stem tertiary structural interactions which stabilize the molecule, contributing a net of DeltaH approximately -30 kcal mol(-1) and DeltaG degrees (37) of -3.3 kcal mol(-1) to a total DeltaH and DeltaG degrees (37) of -121 and -16 kcal mol(-1), respectively, at pH 6.0, 0.5 M K(+) by DSC. Characterization of mutant RNAs supports the presence of a C8(+).G12-C26 loop 1-stem 2 base-triple (pK(a)=6.8), protonation of which contributes nearly -3.5 kcal mol(-1) in net stability in the presence of a wild-type loop 2. Substitution of the nucleotides in loop 2 with uridine bases, which would eliminate the minor groove triplex, destroys pseudoknot formation. An examination of the dependence of the monovalent ion and type on melting profiles suggests that tertiary structure unfolding occurs in a manner quantitatively consistent with previous studies on the stabilizing effects of K(+), NH(4)(+) and Na(+) on other simple duplex and pseudoknotted RNAs.

Structure, stability and function of RNA pseudoknots involved in stimulating ribosomal frameshifting.

Programmed -1 ribosomal frameshifting has become the subject of increasing interest over the last several years, due in part to the ubiquitous nature of this translational recoding mechanism in pathogenic animal and plant viruses. All cis-acting frameshift signals encoded in mRNAs are minimally composed of two functional elements: a heptanucleotide "slippery sequence" conforming to the general form X XXY YYZ, followed by an RNA structural element, usually an H-type RNA pseudoknot, positioned an optimal number of nucleotides (5 to 9) downstream. The slippery sequence itself promotes a low level ( approximately 1 %) of frameshifting; however, downstream pseudoknots stimulate this process significantly, in some cases up to 30 to 50 %. Although the precise molecular mechanism of stimulation of frameshifting remains poorly understood, significant advances have been made in our knowledge of the three-dimensional structures, thermodynamics of folding, and functional determinants of stimulatory RNA pseudoknots derived from the study of several well-characterized frameshift signals. These studies are summarized here and provide new insights into the structural requirements and mechanism of programmed -1 ribosomal frameshifting.