The Effect of Water Coolant and Bur Type on Pulp Temperature When Removing Tooth Structure and Restorative Dental Materials.

OBJECTIVE: The aim was to compare intrapulp temperature (IPT) changes when flat-fissure diamond burs and pear-shaped tungsten carbide burs were used to cut tooth structure, amalgam, and composite resin with and without water coolant. METHODS: Thermocouples were inserted into the pulp chamber of extracted intact mandibular molars. The thermocouples were connected to an electronic thermometer that detects temperature every second to an accuracy of 0.1°C. IPT changes were recorded while using a high-speed handpiece during MOD cavity preparations (n=40), composite resin removal (n=40), and amalgam removal (n=40). A two-way ANOVA was used for each procedure to test for the effect of bur (pear-shaped tungsten carbide vs flat-fissured diamond) and water coolant (on vs off), with significant main effects (α=0.05) further analyzed using Tukey's multiple comparison test. RESULTS: During MOD cavity preparation, water coolant reduced changes in IPT (0.03±0.27°C) compared to no water coolant (1.27±0.29°C) when tungsten carbide burs were used (p<0.05) but not when diamond burs were used. During composite resin removal, tungsten carbide burs had less changes in IPT (0.55±0.18°C) compared to diamond burs (1.66±0.50°C) with no water coolant (p<0.05). Water coolant also reduced changes in IPT (0.09±0.14°C) compared to no water coolant (1.66±0.50°C) when diamond burs were used (p<0.01). Water coolant did not significantly affect IPT when tungsten carbide burs were used. During amalgam removal, tungsten carbide burs had lower changes in IPT (0.56±0.15°C) compared to diamond burs (1.88±0.43°C) with no water coolant (p<0.05). Water coolant also significantly reduced changes in IPT (0.71±0.2°C) compared to no water coolant (1.88±0.43°C) when diamond burs were used (p<0.05) but not when tungsten carbide burs were used. CONCLUSIONS: Water coolant reduced IPT changes when drilling tooth structure with tungsten carbide burs, but not when removing amalgam or composite. Conversely, water coolant reduced IPT changes when drilling with flat fissure diamond burs to remove amalgam and composite, but not when removing tooth structure. When amalgam and composite were removed without water coolant, the tungsten carbide burs resulted in lower IPT changes than when flat fissure diamond burs were used in the same way.

A neotropical perspective on the uniqueness of the Holocene among interglacials.

Understanding how tropical systems have responded to large-scale climate change, such as glacial-interglacial oscillations, and how human impacts have altered those responses is key to current and future ecology. A sedimentary record recovered from Lake Junín, in the Peruvian Andes (4085 m elevation) spans the last 670,000 years and represents the longest continuous and empirically-dated record of tropical vegetation change to date. Spanning seven glacial-interglacial oscillations, fossil pollen and charcoal recovered from the core showed the general dominance of grasslands, although during the warmest times some Andean forest trees grew above their modern limits near the lake. Fire was very rare until the last 12,000 years, when humans were in the landscape. Here we show that, due to human activity, our present interglacial, the Holocene, has a distinctive vegetation composition and ecological trajectory compared with six previous interglacials. Our data reinforce the view that modern vegetation assemblages of high Andean grasslands and the presence of a defined tree line are aspects of a human-modified landscape.

Did the UK's public health shielding policy protect the clinically extremely vulnerable during the COVID-19 pandemic in Wales? Results of EVITE Immunity, a linked data retrospective study.

INTRODUCTION: The UK shielding policy intended to protect people at the highest risk of harm from COVID-19 infection. We aimed to describe intervention effects in Wales at 1 year. METHODS: Retrospective comparison of linked demographic and clinical data for cohorts comprising people identified for shielding from 23 March to 21 May 2020; and the rest of the population. Health records were extracted with event dates between 23 March 2020 and 22 March 2021 for the comparator cohort and from the date of inclusion until 1 year later for the shielded cohort. RESULTS: The shielded cohort included 117,415 people, with 3,086,385 in the comparator cohort. The largest clinical categories in the shielded cohort were severe respiratory condition (35.5%), immunosuppressive therapy (25.9%) and cancer (18.6%). People in the shielded cohort were more likely to be female, aged ≥50 years, living in relatively deprived areas, care home residents and frail. The proportion of people tested for COVID-19 was higher in the shielded cohort (odds ratio [OR] 1.616; 95% confidence interval [CI] 1.597-1.637), with lower positivity rate incident rate ratios 0.716 (95% CI 0.697-0.736). The known infection rate was higher in the shielded cohort (5.9% vs 5.7%). People in the shielded cohort were more likely to die (OR 3.683; 95% CI: 3.583-3.786), have a critical care admission (OR 3.339; 95% CI: 3.111-3.583), hospital emergency admission (OR 2.883; 95% CI: 2.837-2.930), emergency department attendance (OR 1.893; 95% CI: 1.867-1.919) and common mental disorder (OR 1.762; 95% CI: 1.735-1.789). CONCLUSION: Deaths and healthcare utilisation were higher amongst shielded people than the general population, as would be expected in the sicker population. Differences in testing rates, deprivation and pre-existing health are potential confounders; however, lack of clear impact on infection rates raises questions about the success of shielding and indicates that further research is required to fully evaluate this national policy intervention.

Fructose-associated hepatotoxicity indexed by the lactate dehydrogenase isoenzyme LDH-5.

Modern diets have become increasingly rich in fructose, for example through the addition of high-fructose corn syrup to many foods and drinks. It has been suggested that this might lead to hepatotoxicity, including the development of non-alcoholic fatty liver disease. After entering hepatocytes via insulin-independent glucose transporter 2 transmembrane carrier proteins, fructose is phosphorylated to fructose-1-phosphate in a reaction catalysed by fructokinase (ketohexokinase). In turn, fructose-1-phosphate is hydrolysed by aldolase B to glyceraldehydes. Glyceraldehydes may enter gluconeogenesis via fructose-1,6-bisphosphate and fructose-6-phosphate; glyceraldehydes may also enter glycogenolysis via pyruvate. The last pathway involves conversion of pyruvate to acetyl-CoA. Alternatively, pyruvate may be converted, via the action of the hepatic lactate dehydrogenase isoenzyme LDH-5, into lactate. In liver damage, the LDH-5 isoenzyme becomes elevated, predominantly in serum/plasma. We therefore hypothesised that if dietary fructose is associated with hepatotoxicity, there should be a positive correlation between erythrocyte fructose-6-phosphate and plasma LDH-5. This hypothesis was tested by assaying venous blood samples taken from 39 patients at rest, three hours after eating. Quantitative Fourier transform infrared spectrometry following gel electrophoresis was used to assay erythrocyte fructose-6-phosphate levels. Similarly, plasma LDH-5 concentrations were spectrophotometrically analysed, using the pyruvate-lactate reaction, following electrophoretic separation of the LDH isoenzymes. A significant positive correlation was found between the two variables (r = 0.44, p = 0.0047). This result, which supports our hypothesis, is evidence in favour of the possibility that dietary fructose is associated with hepatotoxicity. In addition to being a marker of hepatic damage, LDH-5 may play a more direct epigenetic role in causing liver damage; acute hepatic injury is associated with nuclear translocation of LDH, causing the production of lactate from pyruvate in the nucleus; in turn, the lactate inhibits histone deacetylase and is associated with upregulation of genes associated with the damage response, leading to cell death.

Inverse relationship between human erythrocyte fructose-6-phosphate and short-chain fatty acid levels.

In muscle cells, fructose is initially metabolised to fructose-6-phosphate. In the liver, fructose is metabolised to fructose-1-phosphate and thence to glyceraldehydes, which in turn can either enter glycogenolysis via pyruvate or gluconeogenesis via fructose-1,6-bisphosphate and fructose-6-phosphate. High levels of fructose-1-phosphate inhibit both glycogenolysis and gluconeogenesis. We hypothesised that, if systemically absorbed short-chain fatty acids constitute a major metabolic fate of unabsorbed dietary fructose, then levels of erythrocyte fructose-6-phosphate would be inversely correlated with plasma levels of short-chain fatty acids. The aim of this study was to test this hypothesis in respect of the three main short-chain fatty acids acetate, propionate and butyrate. Venous blood samples from 39 patients (16 male, 23 female, mean (standard error) age 42.4 (3.3) years) were analysed. Erythrocyte fructose-6-phosphate was measured using quantitative Fourier transform infrared spectrometry following gel electrophoresis, while plasma acetate, propionate and butyrate levels were measured using gas-liquid chromatography. The erythrocyte fructose-6-phosphate level was inversely correlated with the plasma acetate (r = -0.30, p = 0.06), propionate (r = -0.31, p = 0.05) and butyrate (r = -0.40, p = 0.01). These results support our hypothesis. The conversion of unabsorbed dietary fructose into short-chain fatty acids may represent a protective mechanism against the adverse effects of hypoglycaemia.

UK national guidelines on the management of syphilis 2015.

These guidelines are an update for 2015 of the 2008 UK guidelines for the management of syphilis. The writing group have piloted the new BASHH guideline methodology, notably using the GRADE system for assessing evidence and making recommendations. We have made significant changes to the recommendations for screening infants born to mothers with positive syphilis serology and to facilitate accurate and timely communication between the teams caring for mother and baby we have developed a birth plan. Procaine penicillin is now an alternative, not preferred treatment, for all stages of syphilis except neurosyphilis, but the length of treatment for this is shortened. Other changes are summarised at the start of the guideline.

Challenges in implementing the new BASHH guidelines for the management of gonorrhoea.

Neisseria gonorrhoeae has progressively developed reduced sensitivity to different classes of antibiotics. The British Association for Sexual Health and HIV (BASHH) updated guidelines for the diagnosis and management of gonorrhoea in 2011. New recommendations include an increased dose of ceftriaxone with adjuvant use of azithromycin, as well as test of cure (TOC) in all cases. We present an audit of adherence to new antibiotic prescribing guidelines as well as TOC uptake in an inner city genitourinary medicine clinic. Among the 271 (242 male, 29 female) patients included, 96% (n = 260) received the new first-line treatment. Test of cure uptake was found to be suboptimal at 55% (n = 149) with the majority (67%) of these taking place within 20 days of treatment. The new first-line treatment for gonorrhoea is feasible and generally accepted by patients. However the TOC uptake is low, emphasising the need for robust follow-up and recall policies. Further study is required into the optimal timing for TOC.

Are we forgetting the children? Testing the children of HIV-positive parents.

Undiagnosed HIV infection in children carries significant risks and national guidelines recommend that children of HIV-positive parents be tested. We reviewed the testing of HIV-positive patients' children in those new to our service from April 2008 to December 2009. Of the 86 women, 95% were asked about children. Of the 243 men, 53 were heterosexual or bisexual, and 190 identified themselves as men who have sex with men (MSM). Parental status was determined in 37 (70%) of heterosexual and bisexual men and in 14 (17%) of 84 MSM with a history of previous female partners. All untested children apart from one lived in their country of origin. In MSM, recording of parental status was uncommon. Following this audit, clinic proformas were changed to document the parental status of men of all sexual orientations, and the HIV status of all children.

British Association for Sexual Health and HIV: framework for guideline development and assessment.

This article has been prepared by the Clinical Effectiveness Group (CEG) of the British Association for Sexual Health and HIV (BASHH) to specify the methodology BASHH requires for guideline development and the process of guideline evaluation by the CEG. This replaces the specifications for the development of UK guidelines on the management of sexually transmitted infections and closely related conditions previously published in this journal in 2004 and updated in 2005.

Management of pyrexia of unknown origin in HIV-positive patients.

Recently, we managed the case of a young HIV-positive man with a pyrexial illness and severe constitutional symptoms, the cause of which was elusive for several weeks. Here we review the causes of pyrexia of unknown origin in HIV-positive individuals, review appropriate investigations and discuss possible empirical treatment when this is required.

Documentation of advice regarding safer sexual practices and partner notification within an HIV clinic.

Guidelines for the sexual health care of our HIV patients and provision of post-exposure prophylaxis following sexual exposure have been produced by both British Association of Sexual Health & HIV and British HIV Association (BHIVA). In the light of recent criminal prosecutions, BHIVA produced guidance for HIV clinical teams regarding discussions with patients about HIV transmission and reducing the risk to sexual partners. This audit examined the advice given to HIV patients with regard to safer sexual practices, sexually transmitted infection screening and partner notification and found that, on the whole, the standards set by national guidelines were adhered to, although areas for improvement were identified. We hope that the introduction of proformas with specific prompts for these subjects for HIV clinic visits will improve clinical standards in this area.

Adherence to antiretroviral therapy in pregnancy.

Successful interventions to prevent congenital HIV require adherence to highly active antiretroviral therapy (HAART) in pregnancy from mothers and agreement with other interventions including mode of delivery and infant testing. We sought to audit adherence support offered antenatally, adherence with HAART, recommendations for delivery and infant testing in women receiving HIV care at our unit and delivering a child in 2004 and 2005. Of the 32 women identified, an adherence discussion was conducted when commencing therapy in 87% and subsequent visits in 77%. Five women were non-adherent with HAART, one disagreed with recommendations for delivery, and attendance at initial post-natal tests was documented in 61%. In general, the British HIV Association guidelines with regard to adherence are followed. Although numbers in this cohort are small, age, ethnicity and pre-pregnancy HIV diagnosis did not seem to affect adherence, but being therapy naïve and poor adherence may predict non-attendance at infant follow-up.

The pattern of plasma sodium abnormalities in an acute elderly care ward: a cross-sectional study.

INTRODUCTION: The combination of ageing, illness, and medications can lead to hyponatraemia or hypernatraemia. AIMS: To describe the distribution of plasma sodium levels in older patients admitted to hospital. METHODS: We carried out a hospital based cross-sectional study examining 1,511 serum sodium concentrations ([Na+]) among 336 elderly patients and attempted to elucidate the cause(s) of the abnormal serum [Na+]. RESULTS: The study population had a mean age of 81.4. Ninety-two (27.4%) patients had hyponatraemia and seven patients (2.1%) had hypernatraemia during their hospitalisation. The distribution of [Na+] results was towards the lower end of the normal range. The mortality rate of patients with hyponatraemia was 14.1% and that of patients with normal serum [Na+] was 8.9%. Six patients with hypernatraemia died in hospital. Lower respiratory tract infection and medication accounted for the majority of cases. CONCLUSIONS: Deranged [Na+] is common among elderly patients admitted to hospital.

Determining the professional attributes of a hospitalist: experience in one Australian metropolitan hospital.

Data were prospectively recorded on 1294 consecutive patients admitted to a General Medical Unit at the Gold Coast Hospital to review the caseload and pre-requisite professional skills of a general physician working as a full-time hospitalist. Based on this review, the general physician hospitalist must possess expertise in the management of common medical conditions and comorbidities, uncommon medical conditions, elderly patients, the seriously ill, the terminally ill, psychiatric patients, surgical patients and patients with dermatologic, ophthalmic and gynaecological problems. The hospitalist must also be proficient in medical education and organization governance. The demonstration of such skills ensures the 'hospitalist' model is efficient and effective for hospital-based care.