Diagnostic and treatment preferences for cracked posterior teeth

BACKGROUND

Longitudinal cracks in teeth are common and often present challenges in diagnosis and management. This study investigated the preferred diagnostic process and treatment modalities for these cracked teeth.

METHODS

Dentists currently registered with Dental Board of Australia and practising within Australia were invited to complete an online Qualtrics-based survey on their perspectives on the presentations, diagnosis, and treatment preferences for cracked teeth.

RESULTS

Of respondents, 56.8% chose to place an indirect cuspal-coverage restoration on an asymptomatic cracked vital tooth. When the tooth was mildly cold sensitive, direct cuspal-coverage restoration was favoured (64.9%), while 36.8% preferred placing an orthodontic band in a tooth with biting pain. Respondents had higher odds of recommending indirect restoration when CAD-CAM milling was available on-site or magnification was routinely used, regardless of presenting symptoms. Almost half (46.8%) preferred to extract if the tooth undergoing root canal treatment had a crack with a 5 mm probing pocket depth. Most (71.4%) demonstrated a poor understanding of cracked tooth biomechanics.

CONCLUSION

Australian dentists varied in their diagnostic and treatment preferences for cracked teeth, reflecting a need for more well-controlled clinical studies in the diagnostic process, clinical biomechanics and treatment modalities for these teeth. © 2023 Australian Dental Association.

Beyond Protein Synthesis; The Multifaceted Roles of Tuberin in Cell Cycle Regulation

The ability of cells to sense diverse environmental signals, including nutrient availability and conditions of stress, is critical for both prokaryotes and eukaryotes to mount an appropriate physiological response. While there is a great deal known about the different biochemical pathways that can detect and relay information from the environment, how these signals are integrated to control progression through the cell cycle is still an expanding area of research. Over the past three decades the proteins Tuberin, Hamartin and TBC1D7 have emerged as a large protein complex called the Tuberous Sclerosis Complex. This complex can integrate a wide variety of environmental signals to control a host of cell biology events including protein synthesis, cell cycle, protein transport, cell adhesion, autophagy, and cell growth. Worldwide efforts have revealed many molecular pathways which alter Tuberin post-translationally to convey messages to these important pathways, with most of the focus being on the regulation over protein synthesis. Herein we review the literature supporting that the Tuberous Sclerosis Complex plays a critical role in integrating environmental signals with the core cell cycle machinery.

Clinical outcomes up-to 10 years of asymptomatic incidental aortic dissections and large aortic aneurysms detected on computer tomography aortography (CTA) prior to transcatheter aortic valve implantation (TAVI)

Background/Introduction

Computer tomography aortography (CTA) is performed routinely to aid planning of transcatheter aortic valve implantation (TAVI). Incidental findings are common, and may influence the decision to proceed with TAVI. The safety and long term outcomes of performing TAVI in patients with previously undiagnosed incidental CT findings of aortic dissections and large aortic aneurysms is currently unknown.

Purpose

To establish the frequency of incidental aortic dissections and large aortic aneurysms prior to TAVI, and subsequent clinical outcomes of patients. We hypothesize that transfemoral access is safe in patients with incidental finding of aortic dissection and large aortic aneurysms.

Methods

This was a retrospective study of 628 sequential TAVI patients in a large, UK tertiary centre between January 2010 and September 2020. Patients were evaluated in 3 groups as per pre-TAVI CTA: incidental aortic dissections, aortic aneurysm >4cm and all others (control group). Endpoints were procedural success, peri-procedural major bleeding and/or vascular complications and/or CVA, length of hospital stay, 30-day and 1-year mortality.

Results

2.9% of patients (n=18) had incidental aortic dissection, of which 66.7% (n=12) were male, with a mean age of 86.7±4.4. 3.8% of patients (n=24) had aortic aneurysms >4 cm. 83.3% (n=20) of them were male and the mean age was 82.8±5.4. Transfemoral approach was favoured in 77.8% of patients in the dissection group and 83.3% of patients in the aneurysm group versus 93.3% in the control group. Procedural characteristics are summarised in Table 1. Vascular access complications, stroke, bleeding and length of hospital stay were comparable between all 3 groups (Table 1). Patients with dissection and large aneurysm had similar success rate of valve implantation compared to the control group (88.9% and 87.5% vs 97.1%, p=0.452). 30-day mortality in the dissection group was higher than the other 2 groups (21.1% vs 0% and 5.6%, p=0.004). Log-rank analysis revealed a higher incidence of MACE in the dissection group over 24 months compared to the other two groups (Figure 1).

Conclusion

A transfemoral approach appears to be a safe choice in patients with incidental findings of aortic dissection or aortic aneurysms >4cm, given no significant difference in terms of valve implant success, vascular injury, major bleeding or unplanned surgical repair. However, patients with stable previous aortic dissections have a significantly higher 30-day mortality and overall lower survival rate over 24 months. This important observation needs to be further investigated in a larger-scale, long-term follow up study, and may in future influence TAVI treatment planning.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Survival curve

New concept: "TARN friendly trauma reporting" (what radiologists say really does matter)

AIM

To establish if detailed review of trauma reports with reference to coding manual improved accuracy of ISS and to establish if demonstrated changes in coding affected performance and tariff payment.

MATERIALS AND METHODS

A study was undertaken which gathered data from 6 months across the five trusts with information on imaging undertaken, mechanism of injury (MOI), Injury Severity Score (ISS), and injury descriptors was included. Patients with ISS near to a best practice tariff boundary of 9 and 16 (5-8 and 11-15) then had their imaging reviewed by the Radiology Department with direct reference to the ISS coding manual. Injuries were then re-coded and ISS recalculated.

RESULTS

Over the 6-month period, 1,693 patients were admitted to the database from the five hospitals. One hundred and sixty-nine (9.9%) patients met the inclusion criteria for review. Thirty-five (20.7%) had a change in abbreviated (region specific) injury code, with 30 a change in the resultant ISS. Three had a decrease in ISS and 27 increased ISS with all 27 moving across an ISS best practice tariff and three moving across two payment tariff boundaries. With re-coding, there was a potential £15,000 of lost revenue from the major trauma centre (MTC) alone.

CONCLUSION

Reporting with reference to ISS description improves the accuracy of ISS significantly. Radiologists improving the descriptions of specific injury patterns and adopting 'Trauma Audit and Research Network friendly' reporting strategies may improve data accuracy, performance, and payment of best practice tariffs to hospitals.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Correction: Discovery, biosynthesis and antifungal mechanism of the polyene-polyol meijiemycin

Correction for 'Discovery, biosynthesis and antifungal mechanism of the polyene-polyol meijiemycin' by Zhen Jie Low et al., Chem. Commun., 2020, DOI: .

Comparison of sporadic and familial behavioral variant frontotemporal dementia (FTD) in a North American cohort

INTRODUCTION

Behavioral variant frontotemporal dementia (bvFTD) may present sporadically or due to an autosomal dominant mutation. Characterization of both forms will improve understanding of the generalizability of assessments and treatments.

METHODS

A total of 135 sporadic (s-bvFTD; mean age 63.3 years; 34% female) and 99 familial (f-bvFTD; mean age 59.9; 48% female) bvFTD participants were identified. f-bvFTD cases included 43 with known or presumed chromosome 9 open reading frame 72 (C9orf72) gene expansions, 28 with known or presumed microtubule-associated protein tau (MAPT) mutations, 14 with known progranulin (GRN) mutations, and 14 with a strong family history of FTD but no identified mutation.

RESULTS

Participants with f-bvFTD were younger and had earlier age at onset. s-bvFTD had higher total Neuropsychiatric Inventory Questionnaire (NPI-Q) scores due to more frequent endorsement of depression and irritability.

DISCUSSION

f-bvFTD and s-bvFTD cases are clinically similar, suggesting the generalizability of novel biomarkers, therapies, and clinical tools developed in either form to the other.

Discovery, biosynthesis and antifungal mechanism of the polyene-polyol meijiemycin

Produced by a newly isolated Streptomycetes strain, meijiemycin is a gigantic linear polyene-polyol that exhibits structural features not seen in other members of the polyene-polyol family. We propose a biosynthetic mechanism and demonstrate that meijiemycin inhibits hyphal growth by inducing the aggregation of ergosterol and restructuring of the fungal plasma membrane.

Low-dose anti-inflammatory combinatorial therapy reduced cancer stem cell formation in patient-derived preclinical models for tumour relapse prevention

Background

Emergence of drug-resistant cancer phenotypes is a challenge for anti-cancer therapy. Cancer stem cells are identified as one of the ways by which chemoresistance develops.

Method

We investigated the anti-inflammatory combinatorial treatment (DA) of doxorubicin and aspirin using a preclinical microfluidic model on cancer cell lines and patient-derived circulating tumour cell clusters. The model had been previously demonstrated to predict patient overall prognosis.

Results

We demonstrated that low-dose aspirin with a sub-optimal dose of doxorubicin for 72 h could generate higher killing efficacy and enhanced apoptosis. Seven days of DA treatment significantly reduced the proportion of cancer stem cells and colony-forming ability. DA treatment delayed the inhibition of interleukin-6 secretion, which is mediated by both COX-dependent and independent pathways. The response of patients varied due to clinical heterogeneity, with 62.5% and 64.7% of samples demonstrating higher killing efficacy or reduction in cancer stem cell (CSC) proportions after DA treatment, respectively. These results highlight the importance of using patient-derived models for drug discovery.

Conclusions

This preclinical proof of concept seeks to reduce the onset of CSCs generated post treatment by stressful stimuli. Our study will promote a better understanding of anti-inflammatory treatments for cancer and reduce the risk of relapse in patients.

Itaconimides as Novel Quorum Sensing Inhibitors of Pseudomonas aeruginosa

Pseudomonas aeruginosa is known as an opportunistic pathogen that often causes persistent infections associated with high level of antibiotic-resistance and biofilms formation. Chemical interference with bacterial cell-to-cell communication, termed quorum sensing (QS), has been recognized as an attractive approach to control infections and address the drug resistance problems currently observed worldwide. Instead of imposing direct selective pressure on bacterial growth, the right bioactive compounds can preferentially block QS-based communication and attenuate cascades of bacterial gene expression and production of virulence factors, thus leading to reduced pathogenicity. Herein, we report on the potential of itaconimides as quorum sensing inhibitors (QSI) of P. aeruginosa. An initial hit was discovered in a screening program of an in-house compound collection, and subsequent structure-activity relationship (SAR) studies provided analogs that could reduce expression of central QS-regulated virulence factors (elastase, rhamnolipid, and pyocyanin), and also successfully lead to the eradication of P. aeruginosa biofilms in combination with tobramycin. Further studies on the cytotoxicity of compounds using murine macrophages indicated no toxicity at common working concentrations, thereby pointing to the potential of these small molecules as promising entities for antimicrobial drug development.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

Disulfide Bond-Containing Ajoene Analogues As Novel Quorum Sensing Inhibitors of Pseudomonas aeruginosa

Since its discovery 22 years ago, the bacterial cell-to-cell communication system, termed quorum sensing (QS), has shown potential as antipathogenic target. Previous studies reported that ajoene from garlic inhibits QS in opportunistic human pathogen Pseudomonas aeruginosa. In this study, screening of an in-house compound library revealed two sulfur-containing compounds which possess structural resemblance with ajoene and inhibit QS in bioreporter assay. Following a quantitative structure-activity relationship (SAR) study, 25 disulfide bond-containing analogues were synthesized and tested for QS inhibition activities. SAR study indicated that the allyl group could be replaced with other substituents, with the most active being benzothiazole derivative (IC₅₀ = 0.56 μM). The compounds were able to reduce QS-regulated virulence factors (elastase, rhamnolipid, and pyocyanin) and successfully inhibit P. aeruginosa infection in murine model of implant-associated infection. Altogether, the QS inhibition activity of the synthesized compounds is encouraging for further exploration of novel analogues in antimicrobial drug development.

Power-efficient III-V/silicon external cavity DBR lasers

We report the design and characterization of external-cavity DBR lasers built with a III-V-semiconductor reflective-SOA with spot-size converter edge-coupled to SOI waveguides containing Bragg grating mirrors. The un-cooled lasers have wall-plug-efficiencies of up to 9.5% at powers of 6 mW. The lasers are suitable for making power efficient, hybrid WDM transmitters in a CMOS-compatible SOI optical platform.

Localized CT-guided irradiation inhibits neurogenesis in specific regions of the adult mouse brain

Radiation is used in the study of neurogenesis in the adult mouse both as a model for patients undergoing radiation therapy for CNS malignancies and as a tool to interrupt neurogenesis. We describe the use of a dedicated CT-guided precision device to irradiate specific sub-regions of the adult mouse brain. Improved CT visualization was accomplished with intrathecal injection of iodinated contrast agent, which enhances the lateral ventricles. T2-weighted MRI images were also used for target localization. Visualization of delivered beams (10 Gy) in tissue was accomplished with immunohistochemical staining for the protein γ-H2AX, a marker of DNA double-strand breaks. γ-H2AX stains showed that the lateral ventricle wall could be targeted with an accuracy of 0.19 mm (n = 10). In the hippocampus, γ-H2AX staining showed that the dentate gyrus can be irradiated unilaterally with a localized arc treatment. This resulted in a significant decrease of proliferative neural progenitor cells as measured by Ki-67 staining (P < 0.001) while leaving the contralateral side intact. Two months after localized irradiation, neurogenesis was significantly inhibited in the irradiated region as seen with EdU/NeuN double labeling (P < 0.001). Localized radiation in the rodent brain is a promising new tool for the study of neurogenesis.

Abstract P6-07-01: CCN3 Impairs Osteoblasts and Stimulates Osteoclast Differentiation To Favor Breast Cancer Metastasis to Bone

Background: The mechanisms underlying the osteotropism of breast cancer are not fully understood. Breast cancer cell lines that aggressively metastasize to bone appear to have increased expression of CCN3 (Nov) compared to those that weakly metastasize to bone. This study aimed to functionally implicate CCN3 in the process of breast cancer metastasis to bone.

Methods: Primary cultures of mouse bone marrow cells were used to assess the effect of recombinant CCN3 protein on RANKL, OPG and on osteoblasts and osteoclasts. To extend data obtained from cell and animal-based models, we have examined CCN3 expression a panel of human breast cancer bone metastases.

Results: CCN3 protein impaired osteoblast differentiation in a dose dependant manner, resulting in an increase in the RANKL/OPG ratio that indirectly favors osteoclast formation. CCN3 also directly induced osteoclast differentiation of RANKL-primer RAW 264.7 monocytes. CCN3 enhanced osteoclast differentiation through its ability to induce calcium mobilization and the subsequent nuclear translocation of NFATc1, a transcription factor essential for osteoclast differentiation. Immunohistochemical staining indicated that CCN3 is readily detectable, both in the breast tumor/stroma and in the majority of breast cancer bone metastasis samples.

Conclusion: Our data support a clinically relevant and important role for CCN3 in modulating the differentiation capacity of bone resident cells to support osteoclast formation and the formation of osteolytic bone metastases.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-07-01.

THE RELATIONSHIP BETWEEN BACTERIAL GROWTH AND PHAGE PRODUCTION

1. The effects of temperature and H-ion concentration on the reaction between antistaphylococcus phage and a susceptible staphylococcus have been studied. 2. The temperature optimum for phage production is in the neighborhood of 35°C. and that for bacterial growth is approximately 40°C. 3. With increasing H-ion concentrations there occur: (a) an increase in the lag phase of bacterial growth without any corresponding increase in the lag phase of phage production; (b) a diminution in the total bacterial population accumulating in the medium without any corresponding drop in the total amount of phage formed. 4. With increasing alkalinity there is no pronounced change in the curves of bacterial growth and phage formation. At pH 8.5 the lytic threshold is increased to about 1000 phage units per bacterium instead of 100–140 as is usually the case and the time of lysis is delayed. 5. By adjusting the medium to pH 6 and 28°C. bacterial growth can be completely inhibited while phage production continues at a rapid rate. 6. Apparently, the previously stressed importance of bacterial growth as the prime conditioning factor for phage formation does not hold, for under certain experimental conditions the two mechanisms can be dissociated.

Management of post-infectious olfactory dysfunction: a nationwide survey of UK ENT consultants

OBJECTIVE

To determine the current practice of UK ENT consultants in investigating cases of suspected post-infectious olfactory dysfunction.

METHOD

We prepared questionnaires and posted these to every consultant ENT surgeon registered with the British Association of Otolaryngologists Head and Neck Surgeons (BAO-HNS). Questions included preferred radiological investigation, smelling test and follow up.

RESULTS

A total of 510 questionnaires were sent, with a response rate of 51%. Most UK consultant ENT surgeons investigated suspected post-infectious olfactory dysfunction by performing either a CT (44%) or an MRI (29%) scan, but only 37% performed formal smell tests. Most consultant ENT surgeons (76%) decide not to follow up post-infectious olfactory dysfunction.

CONCLUSION

This study gives an indication that suspected post-infectious olfactory dysfunction is not investigated thoroughly in the United Kingdom, with only a minority of clinicians performing formal smell tests and a lack of consensus as to radiological investigation. Standardisation of investigations is key to adequately managing suspected post-infectious olfactory dysfunction.

The emerging role of pituitary tumour transforming gene (PTTG) in endocrine tumourigenesis

It is now 10 years since PTTG was first cloned and isolated. Perhaps the major story of the intervening decade of work performed by numerous groups around the world is the sheer multifunctionality ascribed to this gene. PTTG has been implicated in mechanisms of gene transactivation, cell transformation, angiogenesis, metabolism, apoptosis, DNA repair, genetic instability and mitotic control, both in endocrine and non-endocrine settings. In the current review, we cast a critical eye over a decade of PTTG research within the field of endocrine neoplasia.

Infection in acute burn wounds following the Bali bombings: a comparative prospective audit

INTRODUCTION

Bacterial colonisation and invasive bacterial infection remain the major causes of mortality and morbidity following severe burn thus ongoing surveillance of patients and monitoring of infection facilitates early intervention to minimise the risk of sepsis. The circumstances of the Bali bombings in October 2002, provided an opportunity to analyse the ramifications of lengthy transfer times, delayed resuscitation and topical treatment, on the primary incidence of burn wound infection (BWI).

METHOD

This prospective clinical audit investigated the primary incidence of BWI between the usual burn patients admitted to the Burn Unit at Royal Perth Hospital, Western Australia, and a number of survivors from the Bali bombings during a 3-month audit period in 2002. BWI was identified using the Peck et al. proposed definitions for the surveillance of burn wound infections. These include impetigo, surgical wound related infection, cellulitis and invasive infection of unexcised wounds.

RESULTS

The incidence of primary BWI in the Bali-tourist group (68.2%) compared with the standard WA group (18.2%) was significant (p=0.001).

CONCLUSION

Sensitive assessment criteria allowed for early identification of wound infection. A clinically significant difference in the Bali-tourist group is probably related to the circumstances of their injury.

A silver coated dressing reduces the incidence of early burn wound cellulitis and associated costs of inpatient treatment: Comparative patient care audits

In 2000 and 2002, the Royal Perth Hospital (RPH) Burn Unit, Western Australia, conducted two 'before and after' patient care audits comparing the effectiveness and cost of Silvazine (silver sulphadiazine and chlorhexidine digluconate cream) and Acticoat, a new dressing product for in-patient treatment of early burn wounds. The main outcome variables were: burn wound cellulitis, antibiotic use and cost of treatment. Two patient care audits and a comparative sample were used. The two regimes audited were, 'standard treatment' of twice daily showers or washes with 4% chlorhexidine soap and Silvazine cream as a topical dressing (2000, n=51), compared with the 'new treatment' of daily showers of the burn wound with 4% chlorhexidine soap and the application of an Acticoat dressing (2002, n=19). In 2002, costs were also examined using a sample of matched pairs (n=8) of current and previous patients. The main findings were: when using Acticoat the incidence of infection and antibiotic use fell from 55% (28/51) and 57% (29/51) in 2000 to 10.5% (2/19) and 5.2% (1/19) in 2002. The total costs (excluding antibiotics, staffing and surgery) for those treated with Silvazine were US$ 109,357 and those treated with Acticoat were US$ 78,907, demonstrating a saving of US$ 30,450 with the new treatment. The average length of stay (LOS) in hospital was 17.25 days for the Silvazine group and 12.5 days for the Acticoat group-a difference of 4.75 days. These audits demonstrate that Acticoat results in a reduced incidence of burn wound cellulitis, antibiotic use and overall cost compared to Silvazine in the treatment of early burn wounds.

Hearing outcomes in children with primary ciliary dyskinesia--a longitudinal study

Primary ciliary dyskinesia (PCD) is a congenital abnormality of ciliary structure or function. The otological manifestations of the disease include otitis media with effusion (OME). To date, the severity of hearing loss and natural progression of OME in this select group of patients has not been documented. In this retrospective observational study, we looked at the tympanograms and audiograms of all children with PCD attending the Royal Brompton Hospital multidisciplinary clinic. Our results show an improvement in both hearing thresholds and tympanograms with age (p<0.001). Most cases resolve by the age of 12. This supports the current practice of conservative management in these patients. The problems of persistent otorrhoea and residual tympanic membrane perforation are thereby avoided with the reassurance that hearing loss will spontaneously resolve with time.

What do we know about how humans cough?

We review the evidence that activation of the cerebral cortex can lead to movements of the vocal folds and possibly to cough. Electrical stimulation of the motor cortex can cause movements of the vocal folds and vocalizatioin, but cough has not been reported. The motor pathways are via the nucleus ambiguous and possibly the nucleus retroambuigualis in the brainstem. In humans, activation of the cerebral cortex by transcranial magnetic stimulation can cause motor potentials in the intrinsic laryngeal muscles and corresponding surface potentials. The relationships between the cortical sensation related to cough, the voluntary control of cough and the involvement of reflex pathways remain to be clarified.

Thermal oxide based silica ridge waveguide

A silica planar waveguide structure, where a ridge waveguide resides on a vacuum gap, was invented. The silica layer, which was fabricated through thermal oxidation at 1150 masculineC, had an excellent optical index uniformity on the order of 3x10(-5) @1550 nm, and a thickness uniformity of 10 nm at a thickness of 10 microm. Straight waveguide with low insertion loss was demonstrated. Improved thermal efficiency of this structure to cause phase change was discussed in comparison to the conventional channel waveguide structure. Finally, the limitation of this technology to make complex device structures was also explored.

Postmenopausal hormone therapy and risk of stroke: The Heart and Estrogen-progestin Replacement Study (HERS)

BACKGROUND

Observational studies have shown that postmenopausal hormone therapy may increase, decrease, or have no effect on the risk of stroke. To date, no clinical trial has examined this question. To investigate the relation between estrogen plus progestin therapy and risk of stroke among postmenopausal women, we analyzed data collected from the Heart & Estrogen-progestin Replacement Study (HERS), a secondary coronary heart disease prevention trial.

METHODS AND RESULTS

Postmenopausal women (n=2763) were randomly assigned to take conjugated estrogen plus progestin or placebo. Primary outcomes for these analyses were stroke incidence and stroke death during a mean follow-up of 4.1 years. The number of women with strokes was compared with the number of women without strokes. A total of 149 women (5%) had 1 or more strokes, 85% of which were ischemic, resulting in 26 deaths. Hormone therapy was not significantly associated with risk of nonfatal stroke (relative hazard [RH] 1.18; 95% CI 0.83 to 1.66), fatal stroke (RH 1.61; 95% CI 0.73 to 3.55), or transient ischemic attack (RH 0.90; 95% CI 0.57 to 1.42). Independent predictors of stroke events included increasing age, hypertension, diabetes, current cigarette smoking, and atrial fibrillation. Black women were at increased risk compared with white women, and unexpectedly, body mass index was inversely associated with stroke risk.

CONCLUSIONS

Hormone therapy with conjugated equine estrogen and progestin had no significant effect on the risk for stroke among postmenopausal women with coronary disease.

Basic FGF reduces stunning via a NOS2-dependent pathway in coronary-perfused mouse hearts

Basic fibroblast growth factor (FGF-2) may protect the heart from ischemia-reperfusion injury (stunning) by stimulating nitric oxide (NO) production. To test this hypothesis, we pretreated coronary-perfused mouse hearts with 1 microg/ml FGF-2 or vehicle control before the onset of ischemia. Intracellular calcium (Ca(i)(2+)) was estimated by aequorin, and NO release was measured with an NO-selective electrode. Hearts perfused with FGF-2 maintained significantly better left ventricular (LV) function during ischemia than hearts perfused with vehicle. FGF-2 significantly delayed the onset of ischemic contracture and improved LV recovery during reperfusion. Ca(i)(2+) was similar in both groups at baseline during ischemia and reperfusion. L-N(6)-(1-iminoethyl)lysine, a selective inhibitor of inducible NO synthase (NOS2), obliterated the protective effects of FGF-2. In transgenic hearts deficient in the expression of NOS2 (NOS2-/-), FGF-2 did not attenuate ischemia-induced LV dysfunction. Measurements of NO release demonstrated that FGF-2 perfusion significantly increased NO in wild-type but not in NOS2-/- hearts. We conclude that basic FGF attenuates myocardial stunning independent of alterations in Ca(i)(2+) by stimulating NO production via an NOS2-dependent pathway.