Atypical Form of the Fourth Criterion for Transient Entrainment

The typical fourth criterion for transient entrainment is defined when both a sudden shortening in conduction interval to and a distinct change in electrogram morphology at a bipolar recording site are demonstrated while performing overdrive pacing of a reentrant tachycardia from a single pacing site at two different constant rates. The purpose of this article was to test the hypothesis that if an intracardiac recording site showing both orthodromic and antidromic capture with entrainment pacing is located suitably distant from the circuit, sudden shortening in conduction interval to that site may occur without any significant change in the bipolar electrogram morphology (i.e., atypical form of the fourth criterion). Atrial overdrive pacing of orthodromic tachycardia was performed in 20 patients with either left anterior (12 patients) or left posterior (8 patients) accessory pathways. We investigated the effects of overdrive pacing from the proximal or distal coronary sinus, specifically effects on the electrogram interval and the electrogram morphology at the right atrial appendage. Overdrive pacing of orthodromic tachycardia from the proximal coronary sinus was performed in 10 of the 12 patients with left anterior accessory pathways; those 10 patients demonstrated the first entrainment criterion at the right atrial appendage site. Overdrive pacing of orthodromic tachycardia at still shorter cycle lengths demonstrated a sudden shortening in conduction interval to the right atrial appendage site. Despite shortening in conduction interval the morphology of the right atrial appendage electrogram was completely or almost identical to that during orthodromic tachycardia, indicating an atypical form of the fourth criterion. This criterion was not demonstrated in patients with left posterior accessory pathways. Thus, atypical fourth entrainment criterion was demonstrated during overdrive pacing of orthodromic tachycardia from the proximal coronary sinus only in patients with left anterior accessory path ways. Demonstration of atypical fourth criterion seems largely dependent on the location of the accessory pathway, the pacing, and the recording sites.     

Effects of long working hours and the night shift on severe sleepiness among workers with 12‐hour shift systems for 5 to 7 consecutive days in the automobile factories of Korea

We investigated the effects of 12‐hour shift work for five to seven consecutive days and overtime on the prevalence of severe sleepiness in the automobile industry in Korea. [Correction added after online publication 28 Nov: Opening sentence of the summary has been rephrased for better clarity.] A total of 288 randomly selected male workers from two automobile factories were selected and investigated using questionnaires and sleep‐wake diaries in South Korea. The prevalence of severe sleepiness at work [i.e. Karolinska Sleepiness Scale (KSS) score of 7 or higher] was modeled using marginal logistic regression and included theoretical risk factors related to working hours and potential confounding factors related to socio‐economic status, work demands, and health behaviors. Factors related to working hours increased the risk for severe sleepiness at the end of the shift in the following order: the night shift [odds ratio (OR): 4.7; 95% confidence interval (CI): 3.6–6.0)], daily overtime (OR: 2.2; 95% CI: 1.7–2.9), weekly overtime (OR: 1.6; 95% CI: 1.0–2.6), and night overtime (OR: 1.6; 95% CI: 0.8–3.0). Long working hours and shift work had a significant interactive effect for severe sleepiness at work. Night shift workers who worked for 12 h or more a day were exposed to a risk of severe sleepiness that was 7.5 times greater than day shift workers who worked less than 11 h. Night shifts and long working hours were the main risk factors for severe sleepiness among automobile factory workers in Korea. Night shifts and long working hours have a high degree of interactive effects resulting in severe sleepiness at work, which highlight the need for immediate measures to address these characteristics among South Korean labor force patterns.     

Dual suppression with oral contraceptives and gonadotrophin releasing- hormone agonists improves in-vitro fertilization outcome in high responder patients

Certain patients have a tendency for high response to gonadotrophin therapy which is often not ameliorated with prior gonadotrophin- releasing hormone agonist (GnRHa) suppression. As a result, these patients are frequently cancelled and often experience ovarian hyperstimulation syndrome (OHSS) episodes during in-vitro fertilization (IVF)-embryo transfer cycles. Patients with polycystic ovarian syndrome (PCOS) have been noted to be particularly sensitive to exogenous gonadotrophin therapy. We have developed a protocol which is effective in improving IVF outcome in high responder patients, including those with PCOS. Oral contraceptive pills (OCP) are taken for 25 days followed by s.c. leuprolide acetate, 1 mg/day, which is overlapped with the final 5 days of oral contraceptive administration. Low-dose gonadotrophin stimulation is then initiated on the third day of withdrawal bleeding in the form of either human menopausal gonadotrophins or purified urinary follicle-stimulating hormone at a dosage of 150 IU/day. Over a 5 year period, we reviewed our experience utilizing this dual method of suppression in 99 cycles obtained in 73 high responder patients. There were only 13 cancellations prior to embryo transfer (13.1%). The clinical and ongoing pregnancy rates per initiated cycle were 46.5 and 40.4% respectively. Only eight patients experienced mild-moderate OHSS following treatment. For those patients who had undergone previous IVF-embryo transfer cycles at our centre, significant improvements were noted in oocyte fertilization rates, embryo implantation rates and clinical/ongoing pregnancy rates with this protocol. Hormonal analyses revealed that the chief mechanism may be through an improved luteinizing hormone/follicle-stimulating hormone ratio following dual suppression. An additional feature of this dual method of suppression is significantly lower serum androgen concentrations, particularly dehydroepiandrosterone sulphate.      

Coronary risk factors in school children in relation to their family history of coronary heart disease and hyperlipidemia

A school-based study was implemented to assess the family history of coronary heart disease (CHD) and hyperlipidemia (HL) in relation to serum lipoprotein and apolipoprotein levels. One hundred and twenty-five elementary school students (aged9–10 years) and 297 junior high school students (aged12–13 years) participated. Family history was evaluated by the following scoring method: positive family history in a parent. 2 points: in a grandparent. 1 point: and onset of CHD before age 60, 1 additional point. Family history of HL was positive in 8.2% of elementary school students, and 4.2% in junior high school students. Family history of CHD was positive in 11.5% of elementary students, and 11.0% in junior students. Family history score (FHS) for HL was related to serum total cholesterol (TC), low density lipoprotein cholesterol (LDLC), high density lipoprotein cholesterol, apolipoprotein A-T, apolipoprotein B (apoB) and lipoprotein (a) in elementary students, and to TC, LDLC, triglyceride and apoB in junior students. There was no relationship between FHS for CHD and serum lipoprotein or apolipoprotein levels in any student. The children with a positive FH of HL already demonstrated an atherogenic lipid profile while those with FH of CHD did not. which was probably because lipid profiles in children are more genetically mediated by a FH of HL than of CHD.     

American Society for Parenteral and Enteral Nutrition and American Dietetic Association: Standards of Practice and Standards of Professional Performance for Registered Dietitians (Generalist, Specialty, and Advanced) in Nutrition Support

The Standards of Practice for Registered Dietitians in Nutrition Support and the Standards of Professional Performance for the Registered Dietitian in Nutrition Support are key resources for RDs at all knowledge and performance levels. These standards can and should be used by RDs in daily practice to consistently improve and appropriately demonstrate competency and value as providers of safe and effective nutrition support therapy. The standards development and evaluation process is dynamic—these standards will be reviewed at least every 5 years for applicability to practice. Current and future initiatives of A.S.P.E.N. and ADA will provide information that will be used in these updates and in further clarifying and documenting the specific roles and responsibilities of practitioners at each level. As a quality initiative of A.S.P.E.N., its Dietetics Practice Section, ADA, and their DNS DPG, the standards themselves are an application of continuous quality improvement concepts and represent another very important collaborative endeavor.     

How can oral health care providers determine if patients have dry mouth?

BACKGROUND: Dentists recognize the importance of saliva in maintaining oral health and often are familiar with the clinical effects an insufficient salivary flow can have on oral tissues. A variety of medical conditions and medications can alter salivary secretion and composition. Typically, diagnosis of hyposalivation is made only after damage has occurred to the oral tissues. OVERVIEW: The author describes a series of clinical steps that, if followed properly, may help in the early detection of salivary gland hypofunction and prevention of its severe complications. This four-step approach includes identifying a patient's chief complaint and the symptoms and duration of illness that brought the patient to the dentist, as well as any approaches the patient took to relieve symptoms; obtaining a medical history that includes a review of the body systems; performing a clinical evaluation that notes the patient's overall condition in addition to the health and functioning of the salivary glands and oral soft and hard tissues; and, when needed, conducting further diagnostic evaluations. CONCLUSIONS AND CLINICAL IMPLICATIONS: Oral health care providers will continue to face the challenges of treating new and recurrent carious lesions if the profession's approach to salivary hypofunction remains reactive rather than proactive. The recommendations in this article may enhance clinicians' awareness of the objective methods used to identify patients with salivary gland hypofunction or those at risk of developing it. It is hoped that early identification of asymptomatic patients at risk of developing hyposalivation, as well as symptomatic patients will lower the incidence and prevalence of dental caries and fungal infection in this population and ultimately enhance their quality of life.     

Manual versus powered toothbrushes: the Cochrane review

BACKGROUND: In a report released in January 2003, The Cochrane Collaboration Oral Health Group provided a systematic review of the effectiveness of powered versus manual toothbrushes, which generated much interest in the popular press. METHODS: The Cochrane researchers developed and implemented search strategies for the Cochrane Oral Health Group's Trial Register, the Cochrane Central Register of Controlled Trials, MEDLINE and the Cumulative Index to Nursing and Allied Health Literature. They contacted manufacturers for additional information. Trials were selected if they met the following criteria: compared power versus manual toothbrushes, had a randomized design, drew participants from a general population without disabilities, provided data regarding plaque and gingivitis, and were at least 28 days in length. Reviewers evaluated only studies published in 2001 or earlier. Six reviewers from the Cochrane study independently extracted information in duplicate. Indexes for plaque and gingivitis were expressed as standardized values for data distillation. Data distillation was accomplished using a meta-analysis, with a mean difference between powered and manual toothbrushes serving as the measure of effectiveness. RESULTS: The searches identified 354 trials, only 29 of which met the inclusion criteria. These trials involved about 2,500 subjects and provided data for meta-analysis. The results indicated that only the rotating oscillating toothbrush consistently provided a statistically significant, although modest, clinical benefit over manual toothbrushes in reducing plaque and gingivitis. CONCLUSIONS AND CLINICAL IMPLICATIONS: Some powered toothbrushes with a rotation-oscillation action achieve a significant, but modest, reduction in plaque and gingivitis compared with manual toothbrushes.