99mTc internal contaminations measurements among nuclear medicine medical personnel during ventilation - perfusion SPECT lung scans.

This paper presents results of measurements of 99mTc activity concentration in air and nuclear medical personnel blood during ventilation-perfusion SPECT lung scans. 99mTc activity measurements were conducted at the Nuclear Medicine Department, John Paul II Hospital, Krakow. Technicians and nurses who perform examinations were equipped with personal aspirators enabling air sampling to determine the radiation exposure at their workplaces. Measurements allowed to evaluate the concentration of 99mTc in 14 air samples and it ranged from 7800 ± 600 to 10,000 ± 1000 Bq m-3 for air samples collected by technicians and from 390 ± 30 to 600 ± 40 Bq m-3 for air samples collected by nurses. In addition 99mTc concentrations in blood of medical personnel were determined in 24 samples. For technicians the maximum 99mTc blood concentration levels reached 920 ± 70 Bq L-1 and 1300 ± 100 Bq L-1. In the case of nurses, the maximum estimated activity concentrations were about ten times lower, namely 71 ± 7 Bq L-1 and 39 ± 3 Bq L-1. Although the intakes appear to be relatively high, the resulting annual effective doses are about 34 µSv for technicians and only 2 µSv for nurses.

99mTc activity concentrations in room air and resulting internal contamination of medical personnel during ventilation-perfusion lung scans.

This paper presents the results of measurements of 99mTc activity concentrations in indoor air in a nuclear medicine department and resulting estimated 99mTc intake by medical personnel. 99mTc air activity measurements were conducted at the Nuclear Medicine Department, John Paul II Hospital, Krakow, Poland, during ventilation-perfusion SPECT lung scans. Technetium from the air was collected by means of a mobile aerosol sampler with a Petryanov filter operating at an average flow rate of 10 dm3 min-1. Measured activities ranged from 99 ± 11 to 6.1 ± 0.5 kBq m-3. The resulting daily average intake of 99mTc by medical staff was estimated to be 5.4 kBq, 4.4 kBq, 3.0 kBq and 2.5 kBq, respectively, for male technicians, female technicians, male nurses and female nurses. Corresponding annual effective doses were 1.6 µSv for technicians and 1 µSv for nurses. The highest equivalent dose values were determined for extrathoracic (ET) airways: 5 µSv and 10 µSv for nurses and technicians, respectively. It is concluded that estimated annual absorbed doses are over three orders of magnitude lower than the dose limit established in the Polish Atomic Law Act and in recommendations of the International Commission on Radiological Protection for medical staff.

Genetic diversity of urinary bladder cancer and the risk of recurrence based on mutation analysis.

The aim of the study was to assess the genetic diversity of bladder cancer and determine the suitability of a proposed molecular marker panel to monitor the course of bladder cancer patients. The study involved 185 patients with diagnosed bladder cancer. The genetic diversity of the bladder cancer was evaluated by the prevalence of mutations in the TP53, HRAS, FGFR3 and WWOX genes. Mutations were detected in 62.2% of the tumor samples. The most frequently mutated genes were FGFR3 (49.7%) and TP53 (16.2%). No mutation was observed in the WWOX gene. FGFR3 mutations, contrary to TP53, correlated with lower tumor stage and grade, and the presence of multiple tumors. The risk of death was significantly higher in patients with TP53 mutant tumors (HR=3.12; 95%CI: 1.14-7.27; p=0.006) but lower in patients with FGFR3 mutations (HR=0.36; 95%CI: 0.15-0.87; p=0.002). None of the investigated genes was an independent predictor of disease-specific survival, recurrence-free survival or progression-free survival. The results confirm the existence of two alternative pathways of bladder cancer. However the presence of a high percentage of wild type variants in the higher stages of the disease suggest the existence of another pathway of molecular changes leading to the development of bladder cancer. Molecular analysis may have prognostic value and may facilitate the assignment of patients to appropriate forms of treatment - especially in the case of patients with a T1 tumor, where different mutational patterns were observed in each grade.

A prospective study to investigate the relationship between periodontal disease and adverse pregnancy outcome.

OBJECTIVE: This study aimed to investigate a relationship between maternal periodontal disease and preterm birth, low birth weight and late miscarriage. DESIGN: Prospective study in a single centre. SETTING: Guy's and St Thomas' Hospital Trust, London, UK between August 1998 and July 2001. SUBJECTS AND METHODS: Pregnant women were recruited on attending an ultrasound scan at approximately 12 weeks of pregnancy. Subjects completed a questionnaire and underwent periodontal examination. MAIN OUTCOME MEASURES: Plaque and bleeding scores, pocket probing depth and loss of attachment. Pregnancy outcome data was collected retrospectively, including gestational age and birth weight at delivery. RESULTS: Data were collected for 3,738 subjects. Regression analysis indicated that there were no significant relationships between the severity of periodontal disease and either preterm birth (PTB) or low birth weight (LBW). In contrast, there did appear to be a correlation between poorer periodontal health and those that experienced a late miscarriage. CONCLUSIONS: There was no association between either preterm birth or low birth weight and periodontal disease in this population. There is evidence of a correlation between markers of poorer periodontal health and late miscarriage.

Recrudescent herpes labialis during and prior to early pregnancy.

OBJECTIVES: To assess the experience of recrudescent herpes labialis (RHL) before and during early pregnancy. METHODS: History of RHL prior to and during the first trimester of pregnancy was obtained from 3738 women attending at 10-15 weeks' gestation. The influence of age, ethnicity, socioeconomic group, smoking behavior, and alcohol intake on RHL was assessed. RESULTS: 1066 women (28.5%) reported a history of RHL lesions, with reduced incidence of RHL during pregnancy (0.111 lesions/subject per month) compared with outside pregnancy (0.19 lesions/subject per month) (P<0.0001). Those who did report lesions during pregnancy (n=296) experienced them at a higher monthly rate (0.41 lesions/subject per month) than before pregnancy (0.25 lesions/subject per month) (P<0.0001). RHL rate in early pregnancy was related solely to the previous rate of lesion recrudescence (P<0.001). CONCLUSION: Pregnant women with a history of RHL report reduced incidence of RHL during pregnancy.

Periodontal health of London women during early pregnancy.

OBJECTIVES: A descriptive cross-sectional study to determine the severity of periodontal disease in early pregnancy and its relation to demographic variables in a South East London population. METHODS: 2,027 pregnant women attending Guy's Hospital for an ultrasound scan at 10 to 14 weeks gestation were assessed. Data were collected via questionnaire and periodontal examination, including plaque and bleeding scores, pocket probing depth and loss of attachment. RESULTS: Mean age was 29.8 years (sd 5.5). Of these, 61.8% were white, 28.5% black, and 9.7% of other ethnic group. A total of 15% reported smoking during pregnancy. The mean number of teeth present was 28 (sd 2) per subject, mean percentage of sites with plaque present was 60.5% (sd 22.6), mean pocket depth was 2.0 mm (sd 0.4), mean loss of attachment was 0.4 mm (sd 0.3), and the mean percentage of sites bleeding on probing was 20.2% (sd 16.3). Linear regression demonstrated that probing depth was related to age, ethnicity, socioeconomic status and plaque score but not to smoking whereas loss of attachment demonstrated relationships with age, smoking status and plaque score but not ethnicity or socioeconomic status. CONCLUSION: There was a relatively high proportion of subjects with deep periodontal pockets in this pregnant population compared to the Adult Dental Health Survey 1998 but with similar levels of loss of attachment and percentage of sites with plaque present. Several demographic factors were associated with the level of periodontal disease in this population.

The relationship of health beliefs and psychological mood to patient adherence to oral hygiene behaviour.

Patient adherence to oral hygiene instructions (compliance) is important for the success of periodontal treatment. However, there are many different definitions and measures of what constitute patient adherence. Also, many different models of patient behaviour have been studied, with inconsistent or conflicting findings. The purpose of this study was to explore the relationships between health beliefs (three aspects of dental health locus of control, health values and adherence intent), psychological mood and periodontal outcomes. Complete periodontal data were obtained for 47 untreated patients prior to instruction in oral hygiene, and again 4-6 weeks later. Psychological variables were measured by questionnaire and adherence was measured by reductions in clinical variables (plaque and inflammation). Data were analysed using an item analysis of the questionnaire to assess the internal consistency of the subscales. The results showed overall stability in the psychological variables and reductions in the clinical variables. The main result was a series of negative associations between plaque scores and adherence intent. Inflammatory variables showed some association with psychological constructs related to dependence on external factors.

Platelet membrane fluidity and intraplatelet Ca2+ mobilization are affected in uraemia.

In present investigations, platelet membrane fluidity and intraplatelet Ca2+ mobilization were analysed in uraemic platelets by fluorescence techniques. Thirteen non-dialyzed uraemic patients and 16 control subjects were examined. Anisotropy of DPH-probe, measured at 37 degrees C, was significantly higher in control (0.2236 +/- 0.0050) than in uraemic platelets (0.1969 +/- 0.0082; p < 0.01). There was no difference between control (109.8 +/- 6.0 nM) and uraemic platelets (100.0 +/- 7.3 nM) when the basal [Ca2+]i in resting platelets was determined. Activation of platelets by ADP (12.5 microM) or by thrombin (0.1 U/ml) resulted in an increase in [Ca2+]i. It was significantly higher (p* < 0.003 for ADP and p* < 0.009 for thrombin, respectively) in control platelets (383.6 +/- 56.3 nM and 2031.0 +/- 298.8 nM, respectively) than in uraemic ones (191.0 +/- 21.3 nM and 838.7 +/- 144.1 nM, respectively). The amount of released Ca2+ was higher in control platelets activated by both ADP and thrombin (157.6 +/- 21.4 nM and 409.3 +/- 71.0 nM, respectively) than in uraemic platelets (76.7 +/- 15.7 nM and 203.0 +/- 29.3 nM, respectively) and the differences were significant (p < 0.01 and p* < 0.01, respectively). These results indicate an abnormal intracellular Ca2+ mobilization in uraemic platelets. Both increased membrane fluidity and decreased Ca2+ mobilization should be considered as a possible reason of reduced fibrinogen receptor exposure on uraemic platelets.

Platelet membrane fluidity and intraplatelet Ca2+ homeostasis are affected in uremia.

Recently we have described a dependence of platelet disability in thrombosis upon the progression in renal failure and an elevated level of RGDS-containing degradation products in uremic plasma, which is also correlated with progression in renal failure. Based on fluorescence techniques, our present investigations concerned possible changes in platelet membrane fluidity and intraplatelet calcium homeostasis in uremic platelets. Washed platelets loaded with DPH or with Fura-2 were examined with LS-50 luminescence spectrometer. Light anisotropy of DPH measured at 37 degrees C was significantly higher in control platelet membranes than in uremic ones. It can be considered as more fluidic membranes of uremic platelets. No difference between the basal intraplatelet calcium level was found for uremic and control platelets, but in the presence of 5 mM EGTA, the basal level was reduced significantly deeper in uremic platelets. Activation of platelets by both ADP (12.5 microM) and thrombin (0.1 U/ml) resulted in rapid increase in the intraplatelet calcium level in the examined platelets, but this increase was significantly higher for control platelets. The results indicate an abnormal intracellular calcium homeostasis in uremic platelets, which is associated with an increased fluidity of platelet membranes in uremia.

Concentration of RGDS-containing degradation products in uremic plasma is correlated with progression in renal failure.

A concentration of protein degradation products containing the RGDS sequence, which could contribute to a lower reactivity of uremic platelets, has been estimated in both uremic (n = 16) and control (n = 7) plasmas. Degradation products and other small molecules were separated from plasma by filtration through AMICON YM-10 filter. RGDS antigen was determined in filtered material using the radioimmunoassay method based on monospecific anti-RGDS rabbit polyclonal antibodies. The concentration of RGDS-containing degradation products in uremic plasma ranged from 0.8 to 353 nM with mean value 58.6 +/- 24.9 nM and was higher than in control (0.7 to 5.9 nM, mean value 2.1 +/- 0.9 nM). Moreover, the level of RGDS-antigen positively correlated with plasma creatinine concentration (R = 0.87, p < 0.001). The filtered material showed an inhibitory effect on fibrinogen binding to control platelets in respect to RGDS-antigen concentration. We conclude that the elevated concentration of RGDS-containing degradation products in uremic plasma is partially responsible for bleeding tendency in renal failure.