Technical quality of root canal treatment in Taiwan

AIM: To evaluate the current technical quality of root canal treatment (RCT) in Taiwan. METHODOLOGY: A total of 1085 RCT cases, randomly selected from a large sample and representative of the Taiwanese population from April to September 2000, were evaluated by eight endodontic specialists. The qualitative evaluation of RCT cases was based on two variables: length of the root filling and density of the obturation. A root canal with both adequate filling length (the apical termination of the root filling within 2 mm of the radiographic apex) and complete obturation (no lateral or apical canal lumen visible in the apical one-third of the root canal) was defined as having good-quality endodontic work (GQEW). A tooth was defined as having a GQEW when all its canals were categorized as GQEW. RESULTS: From a total of 1867 root canals, overfilling occurred in 235 (12.6%), adequate filling length in 1152 (61.7%), underfilling in 466 (25.0%) and no filling in 12 (0.6%). Of the 1867 root canals, 710 (38.0%) demonstrated complete obturation and 1157 (62%) demonstrated incomplete obturation. GQEW was found in 650 (34.8%) root canals and 329 (30.3%) teeth. The percentage of teeth with GQEW in hospital cases (38.1%) was significantly greater (P < 0.001) than that in private clinic cases (24.3%). In addition, the frequency of teeth with GQEW in the anterior teeth (40.4%) or in the premolars (33%) was significantly greater (P < 0.001) than that in the molars (18.4%). CONCLUSIONS: Approximately 70% of the teeth receiving RCT in Taiwan were either of inadequate filling length or sealing density.     

Cutaneous vascular reactivity is reduced in aging and in heart failure: association with inflammation

In the present study, we have investigated whether changes in vascular reactivity in congestive heart failure (CHF) patients can be detected in the cutaneous microvessels and whether these changes are due to endothelial dysfunction, are affected by increasing age and related to an ongoing inflammation. The responses to local warming and iontophoretically administered endothelium-dependent and -independent vasodilators were investigated in healthy young adults, healthy elderly adults and elderly adults with CHF. The results were correlated with plasma concentrations of vascular risk factors and markers for endothelial dysfunction and inflammation. The vasorelaxant responses were reduced in the elderly groups and were attenuated further in the CHF group. This group also had increases in levels of several markers associated with inflammation, higher blood glucose and homocysteine levels, a lower low-density lipoprotein-cholesterol and a rise in the concentration of von Willebrand factor, indicating a prothrombotic endothelial function. The severity of the heart failure, measured as the plasma level of brain natriuretic peptide, correlated with the intensity of inflammation and to the changes in vascular risk factors and endothelial function. It is concluded that the reactivity of the cutaneous microvessels is reduced with age, and the presence of CHF causes a further impairment. There is endothelial dysfunction in CHF, but it is uncertain to what extent this contributes to the reduced vasodilatory capacity. The inflammatory response appears central for many of the manifestations of the CHF syndrome.     

Longitudinal evolution of HIV-1-associated lipodystrophy is correlated to serum cortisol:DHEA ratio and IFN-alpha

BACKGROUND: We have previously shown that lipid alterations in HIV-1-associated lipodystrophy (LD) are correlated with decreased serum dehydroepiandosterone (DHEA) and increased cortisol:DHEA ratio and IFN-alpha levels. OBJECTIVE: To evaluate in a longitudinal study whether steroid and cytokine modifications are associated with the evolution of physical changes and lipid alterations associated with LD. METHODS: Thirty-four HIV-1-positive men were followed during 32.5 +/- 4.0 months and tested at four time-points. The patients were subdivided into five groups according to physical changes and anthropometric measurements: LD-negative, initially LD-negative becoming LD-positive, LD-positive unchanged, aggravated or improved. Serum lipids, apolipoproteins, adrenal steroids and cytokines were measured and compared with baseline values. RESULTS: (1) LD aggravation is associated with persistent elevated lipids, a decrease in serum DHEA, an increase in cortisol:DHEA ratio and persistent high levels of IFN-alpha. (2) LD improvement is associated with normalization of serum lipids, an increase in serum DHEA leading to normalization in cortisol:DHEA ratio, and normalization of IFN-alpha levels. (3) In LD-positive men evolution of VLDL cholesterol is negatively correlated with DHEA (r = -0.56, P < 0.01) and positively with cortisol:DHEA ratio (r = 0.62, P < 0.004) and with IFN-alpha (r = 0.57, P < 0.01). (4) The switch to LD is associated with a decrease in serum DHEA. (5) Patients who remained LD-negative maintained normal lipids, elevated cortisol and DHEA, and normal cortisol:DHEA ratio and normal levels of IFN-alpha. CONCLUSIONS: This study indicates that cortisol:DHEA ratio and serum IFN-alpha levels are closely associated with clinical evolution and atherogenic lipid alterations in LD.     

Ghrelin-induced GH secretion in domestic fowl in vivo and in vitro

Although avian and mammalian species differ significantly in their regulation of GH secretion, preliminary studies have demonstrated in vivo GH responses to ghrelin in chickens, as in mammals. However, the relative potency of ghrelin as a GH-releasing hormone (GHRH) in birds is uncertain, as is its site of action.The intravenous administration of human ghrelin to immature chickens promptly increased the circulating GH concentration (within 10 min), although this was transitory and was only maintained for 20 min. This GH response was dose-related with an EC50 of approximately 3.0 microg/kg, comparable with the reported potency of human GHRH in chickens. When incubated with dispersed pituitary cells, human ghrelin induced dose-dependent GH release over a range of 10(-6) to 10(-9) M, with an EC50 of 7.0 x 10(-8) M, comparable with that induced by human GHRH (EC50 6.0 x 10(-8) M), although it was less effective at doses of 10(-6) to 10(-8) M. This was due to direct effects on pituitary somatotrophs, since human ghrelin increased GH release (determined by the reverse hemolytic plaque assay) from individual pituitary cells. The incubation of these cells with human ghrelin induced a dose-dependent increase in the numbers of somatotrophs secreting GH and in the amount of GH released by each cell. In summary, these results demonstrated that ghrelin is a dose-related GH-releasing factor in chickens with a potency comparable with that induced by human GHRH. The GH-releasing action of ghrelin is due, at least in part, to stimulatory actions on the numbers of somatotrophs induced to release GH and upon the amount of GH released from individual somatotrophs.     

Whole blood and red cell ATP content in patients with peripheral vascular disease: the effect of cigarette smoking and oxpentifylline

The relationship between erythrocyte ATP content and the presence of atherosclerotic peripheral occlusive vascular disease was investigated. In 20 elderly patients with severe peripheral vascular insufficiency (10 male, 10 female; age 68.8 +/- 12.5 years; Mean +/- SD) the mean erythrocyte ATP content was 1.57 +/- 0.16 mmol/litre. In a sex and age matched group (69.1 +/- 9.6 years) with no signs or symptoms of peripheral or myocardial ischaemia, erythrocyte ATP content did not differ significantly (1.49 +/- 0.29 mmol/litre). In young healthy volunteers, there was no difference in erythrocyte ATP content between males and females or between cigarette smokers and non-smokers, nor were the values for the young group different from those obtained from the elderly patients. The effect of oxpentifylline administration on erythrocyte ATP levels in patients with peripheral vascular disease was also studied. Administration of oxpentifylline (1.6 g per day in divided doses) over 7 days had no effect on erythrocyte ATP content in 10 patients (5 male, 5 female) with ischaemic lower limbs. These results suggest that measurement of erythrocyte ATP content is unlikely to be a useful index in the assessment of peripheral vascular disease.     

Ex vivo expansion of megakaryocyte precursor cells in autologous stem cell transplantation for relapsed malignant lymphoma

To evaluate the impact of ex vivo expanded megakaryocyte (MK) progenitors on high-dose chemotherapy-induced thrombocytopenia, we conducted a phase II study in 10 patients with relapsed lymphoma. Two fractions of peripheral blood progenitor cells (PBPC) were cryopreserved, one with enough cells for at least 2 x 10(6) CD34+ cells/kg and a second obtained after CD34+ selection. Ten days before autologous stem cell transplantation, the CD34+ fraction was cultured with MGDF+SCF for 10 days. After BEAM (BCNU, cyclophosphamide, cytarabine, and melphalan) chemotherapy, patients were reinfused with standard PBPC and ex vivo expanded cells. No toxicity was observed after reinfusion. The mean fold expansion was 9.27 for nucleated cells, 2 for CD34+ cells, 676 for CD41+ cells, and 627 for CD61+ cells. The median date of platelet transfusion independence was day 8 (range: 7-12). All patients received at least one platelet transfusion. In conclusion, ex vivo expansion of MK progenitors was feasible and safe, but this procedure did not prevent BEAM-induced thrombocytopenia. Future studies will determine if expansion of higher numbers of CD34+ cells towards the MK-differentiation pathway will translate into a functional effect in terms of shortening of BEAM-induced thrombocytopenia.     

Myocardial infarction and coronary pathology in severely obese people examined at autopsy

OBJECTIVE: To find out the severity of coronary atherosclerosis and its relationship to body structure and adiposity in severely obese people with body mass index (BMI) > or = 35.0 kg/m(2) and to examine the incidence and characteristic features of myocardial infarction and other fatal coronary events in this population. DESIGN: Autopsy reports were analyzed, including data on age, height, weight, abdominal subcutaneous fat thickness, heart weight, coronary atherosclerosis, histopathology and toxicology. Myocardial collagen and arteriolar structure were examined by computerized image analysis. SUBJECTS: Forensic autopsy cases (n=166) with a BMI > or = 35.0 kg/m(2) examined in 1992-1998 were collected from the files of the Department of Forensic Medicine, University of Oulu, Finland. RESULTS: In a large number of the severely obese individuals, the coronary arteries were either lesion-free or only fatty streaks were observed (38% of men, 44% of women) and coronary thrombosis was rare (3.8% of men and 1.6% of women). Cardiac causes of death predominated, cardiomyopathy being the commonest. Myocardial infarction was the immediate cause of death in 14.4% of men and 12.9% of the women, and it was associated with increased heart size in men. Coronary atherosclerosis without any infarction had been determined as the cause of death in 8.6% of the men and 8.1% of the women. Abdominal subcutaneous fat thickness had a significant negative association with the severity of coronary atherosclerosis in the women, and a decrease in the arteriolar media/lumen ratio with increasing BMI was observed in the men. CONCLUSIONS: A considerable number of severely obese people have only fatty streaks and no marked stenosis in their coronary arteries, even at an advanced age. The large amounts of subcutaneous adipose tissue in obese women may provide some protection against coronary lesion development, which could be an estrogen effect. Myocardial infarction in severely obese men is associated with cardiac hypertrophy. The significance of the BMI-related dilatation of the myocardial arterioles in men and its relationship to a remodelling of the epicardial arteries will require future investigations.     

The growth hormone/insulin-like growth factor-I axis hormones and bone markers in elite athletes in response to a maximum exercise test

The aim of the GH-2000 project is to develop a method for detecting GH doping among athletes. Previous papers in the GH-2000 project have proposed that a forthcoming method to detect GH doping will need specific components from the GH/IGF-I axis and bone markers because these specific variables seem more sensitive to exogenous GH than to exercise. The present study examined the responses of the serum concentrations of these specific variables to a maximum exercise test in elite athletes from selected sports. A total of 117 elite athletes (84 males and 33 females; mean age, 25 yr; range, 18-53 yr) from Denmark, the United Kingdom, Italy, and Sweden participated in the study. The serum concentrations of total GH, GH22 kDa, IGF-I, IGF binding protein (IGFBP)-2, IGFBP-3, acid-labile subunit, procollagen type III (P-III-P), and the bone markers osteocalcin, carboxy-terminal cross-linked telopeptide of type I collagen (ICTP), and carboxy-terminal propeptide of type I procollagen were measured. The maximum exercise test showed, in both genders, a peak concentration of total GH (P < 0.001) and GH22 kDa (P < 0.001) by the time exercise ended compared with baseline, and a subsequent decrease to baseline levels within 30-60 min after exercise. The mean time to peak value for total GH and GH22 kDa was significantly shorter in males than females (P < 0.001). The components of the IGF-I axis showed a similar pattern, with a peak value after exercise compared with baseline for IGF-I (P < 0.001, males and females); IGFBP-3 (P < 0.001, males and females); acid-labile subunit [P < 0.001, males; not significant (NS), females], and IGFBP-2 (P < 0.05, females; NS, males). The serum concentrations of the bone markers ICTP (P < 0.001, males; P < 0.05, females) and P-III-P (P < 0.001, males and females) increased in both genders, with a peak value in the direct post-exercise phase and a subsequent decrease to baseline levels or below within 120 min. The osteocalcin and propeptide of type I procollagen values did not change during the exercise test. Specific reference ranges for each variable in the GH/IGF-I axis and bone markers at specific time points are presented. Most of the variables correlated negatively with age. In summary, the maximum exercise test showed a rather uniform pattern, with peak concentrations of the GH/IGF-I axis hormones and the bone markers ICTP and P-III-P immediately after exercise, followed by a subsequent decrease to baseline levels. The time to peak value for total GH and GH22 kDa was significantly shorter for females compared with males. This paper presents reference ranges for each marker in each gender at specific time points in connection to a maximum exercise test to be used in the development of a test for detection of GH abuse in sports.