Analytical performance and clinical decision limit of a new release for cardiac troponin I assay

Background

Cardiac troponins (cTns) are the ‘gold standard’ biomarker for the diagnosis and prognosis of acute coronary syndrome. Analytical performance is critical at low concentrations of cTn, and many of the current assays do not meet the guideline requirement of a 10% coefficient of variation (CV) at the 99th percentile concentrations. The aim of the study was to establish if the newly released Access® AccuTnI®+3 (AccuTnI+3) cardiac troponin I assay (Beckman Coulter Inc., Brea, CA, USA) reached this objective.

Methods

All AccuTnI+3 assays were performed on UniCel® DxI800 analyzer (Beckman Coulter Inc). Limit of Blank (LoB), Limit of Detection (LoD) and Limit of Quantitation (LoQ) were determined according to Clinical Laboratory Standard Institute EP17-A and EP5-A2 protocols. The 99th percentile upper reference limit (URL) was determined by analysing serum samples from 330 apparently healthy blood donors (260 men, 70 women, age range 18–70 years, median age 36 years).

Results

LoB and LoD values were 2.6 and 12 ng/L, respectively. The 10% CV was at 18 ng/L (95% confidence interval [CI] 8–25). The 99th percentile URL was 22 ng/L (95% CI 11–34).

Conclusions

The newly released assay has improved low-end analytical performance and reaches the goal of having a total imprecision ≤10% at 99th percentile of a healthy reference population (guideline acceptable). With this assay, it is now possible to utilize the 99th percentile as decision level for myocardial injury detection.

Tamoxifen-related endocrine symptoms in early breast cancer patients are relieved when it is switched to anastrozole

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Background: To determine how menopausal symptoms and quality of life changed when adjuvant tamoxifen has been suspended for any reason in favor of anastrozole in early breast cancer (BC) patients (pts). Methods: Major inclusion criteria: severe side effects or serious potential diseases caused by tamoxifen (20 mg die) that switched to anastrozole (1 mg die); confirmed early BC radically resected and with positive hormonal receptors; postmenopausal status; adjuvant chemo and/or radiotherapy suspended at least 4 wks before the hormonal switch. Exclusion criteria: discontinuation of tamoxifen for endocrine symptoms. Menopausal symptoms and health-related quality of life were assessed by the series of Functional Assessment of Cancer Therapy-Breast (FACT-B) plus endocrine subscale (ES) questionnaires at the switch and 3, 6, 9, and 12 months later. Sample size was decided by the effect size method (SD fixed as 0.5, effect of medium value). Score modifications were evaluated by one-way ANOVAS. Results: From Feb 2002 to Jun 2003, a total of 44 women were enrolled into the study. Discontinuation of tamoxifen was for: asymptomatic uterine problems (endometrium thickening or fibromatosis) in 56% of pts; cardiovascular disorders (mainly leg thrombosis and phlebitis) in 18%; patient’s refusal in 9%; GI persistent side effects in 5%; other reasons in 12% of pts. Endocrine symptoms ameliorated between baseline and 3 months, and stabilized thereafter. Mean ES scores improvement from baseline test was +3 (95% CI, 1 to 5), +4 (95% CI, 3 to 6), +5 (95% CI, 3 to 7), and +4 (95% CI, 3 to 6) at 3, 6, 9 and 12 months, respectively. FACT-ES global score had a mean improvement during 1-yr period of 9 points (95% CI 6 to 13, p < .0005), with 22 patients (50%) ever reaching an increase ≥ 5% of the baseline score. There also was a significant improvement in TOI score (+4 points, 95% CI 2 to 6, p < .0005), and physical and breast cancer subscales (+2, 95% CI 1 to 2, p < .001, and +1, 95% CI, 1 to 2, p < .001, respectively). Pts receiving anastrozole reported higher rate of mild arthritic and bone pain (27% vs 7%, p = .021). Conclusion: When a patient develops an endocrine symptom while on tamoxifen, a change in favor of anastrozole should be considered to minimize those symptoms and to improve quality of patient’s life.

No significant financial relationships to disclose.

[Critical comparison of some questionnaires for the evaluation of the quality of life in children affected by asthma]

AIM

The aim of this study was to critically compare 9 different questionnaires for the evaluation of the Quality of Life in children affected by asthma.

METHODS

The questionnaires were analyzed by considering their psychometric characteristics (reliability, validity, responsiveness, least clinically relevant difference), together with other practical and technical aspects (number of items, number and kind of domains, scaling of items, scoring, time to complete). Data were obtained from the scientific literature.

RESULTS

Only 1 of the 9 analyzed questionnaires (Pediatric Asthma Quality of Life Questionnaire, PAQLQ) appears fully validated from a psychometrical standpoint. Moreover, it is the only one to have a validate translation into the Italian language.

CONCLUSIONS

The authors suggest the use of the PAQLQ as tool of choice in the evaluation of the Quality of Life in children affected by asthma.

Is the birthdate a risk factor for congenital hypothyroidism? A statistical answer based on personal experience

BACKGROUND

To verify statistically the hypothesis that birthdate represents a risk factor for Congenital Hypothyroidism, as proposed by some European Authors. Moreover, to verify the existence of seasonal cyclic trends in TSH levels.

METHODS

For the verification of birthdate as a risk factor, we considered retrospectively a data set of all consecutives newborns of Marche Region (Italy) affected by Congenital Hypothyroidism, in the period 1981-1996 (n = 92). For the evaluation of seasonal cyclic trends in TSH, we considered the level of the hormone in all newborns of Marche Region screened in the period 1989-1996. Data were collected from Neonatal Screening Register of Marche Region. All the statistical analyses are based on circular statistics techniques (Rayleigh test, Roger test, estimation of density by kernel method, Mardia test for circular-linear correlation, Maximization of Mean Vector Length).

RESULTS

No cyclic trend was pointed out with regard to Congenital Hypothyroidism; neither seasonal rhythms nor other cyclic patterns of TSH levels were evidenced.

CONCLUSIONS

Neither the hypothesis of birthdate as a risk factor for Congenital Hypothyroi-dism, nor the existence of seasonal variations in TSH hormone releasing were confirmed.

Lamivudine treatment failure in preventing fatal outcome of de novo severe acute hepatitis B in patients with haematological diseases

BACKGROUND

Patients with malignant haematological diseases administered or no longer receiving immunosuppressive therapy are at high risk of reactivation or de novo hepatitis B infection and fulminant hepatitis. Despite promising results in the treatment of chronic hepatitis and its use in selected patients with acute hepatitis B, there is no consensus on lamivudine treatment in severe acute hepatitis portending a fatal clinical outcome.

CASE REPORTS

Of the ten patients with malignant haematological disorders who became infected with the same strain of hepatitis B virus during hospitalisation in a haematology ward, five received lamivudine (and in some cases, ganciclovir and famciclovir). The other patients received only supportive therapy, since deteriorating clinical conditions hampered specific treatment efforts. Eight patients died from acute liver failure and one from a fatal course of the haematological disease; one had a favourable outcome from the therapy. There was no significant difference in terms of survival between the treated and untreated patients.

CONCLUSIONS

Although lamivudine has proved promising in the therapy of chronic hepatitis B and of recurrent hepatitis after liver transplantation, its use in de novo severe acute hepatitis should be investigated further, particularly in immunocompromised patients.

Fine structural modifications of liver, pancreas and brown adipose tissue mitochondria from hibernating, arousing and euthermic dormice

An ultrastructural and morphometric study was performed on mitochondria of euthermic, hibernating and arousing hazel dormice (Muscardinus avellanarius), in order to investigate possible modifications during the seasonal cycle. Hepatocytes, pancreatic acinar cells and brown adipocytes were considered. Our results demonstrated that: (1) the general morphology of mitochondria of all cell types shows slight modifications during the seasonal cycle; (2) mitochondrial size and inner membrane length significantly increase from euthermia to hibernation and decrease upon arousal in all cell types; (3) mitochondrial matrix granules drastically increase in number during hibernation and decrease upon arousal in hepatocytes and pancreatic acinar cells, whereas they do not change in brown adipocytes. These structural modifications are probably related to the changes in cellular energy needs during the euthermia-hibernation-arousal cycle.

Some unexpected results in time distribution analysis of spontaneous deliveries

OBJECTIVE

To study time distribution of spontaneous deliveries.

METHODS

A retrospective analysis of 1,791 spontaneous deliveries over a 4-year period (1993-1996) was made at the department of Obstetrics and Gynaecology, Civil Hospital, Fano, Italy. Circular statistics techniques (maximization of mean vector length) were used.

RESULTS

Some unexpected infradian disuniformities (with 60- and 90-hour periods) were observed. Moreover, a correlation between the distribution of spontaneous deliveries and the lunar phases was found.

CONCLUSIONS

In this study, some unexpected infradian disuniformities were found. However, no biological explanations appear to be reasonable in light of current knowledge, so the interpretation of these results remains an open question.

Ultrastructural, morphometrical and immunocytochemical analyses of the exocrine pancreas in a hibernating dormouse

Pancreatic acinar cells of euthermic, hibernating and arousing individuals of the hazel dormouse Muscardinus avellanarius (Gliridae) have been observed at the electron-microscopic level and analysed by means of ultrastructural morphometry and immunocytochemistry in order to investigate possible fine structural changes of cellular components during periods of strikingly different degrees of metabolic activity. During hibernation, the cisternae of the rough endoplasmic reticulum (RER) flatten assuming a parallel pattern, the Golgi apparatus is extremely reduced and the mitochondria contain many electron-dense particles. The cell nuclei appear irregularly shaped, with deep indentations containing small zymogen granules. They also contain abundant coiled bodies and unusual constituents, such as amorphous bodies and dense granular bodies. Large numbers of zymogen granules occur in all animals. However, the acinar lumina are open and filled with zymogen only in euthermic animals, whereas, in hibernating and arousing individuals, they appear to be closed. Morphometrical analyses indicate that, in pancreatic acinar cells, nuclei and zymogen granules significantly decrease in size from euthermia to hibernation, probably reflecting a drastic decrease of metabolic activities, mainly protein synthesis and processing. In all the studied animals, immunocytochemistry with specific antibodies has revealed an increasing gradient in alpha-amylase content along the RER-Golgi-zymogen granule pathway, reflecting the protein concentration along the secretory pathway. Moreover, during deep hibernation, significantly larger amounts of alpha-amylase accumulate in RER and zymogen granules in comparison to the other seasonal phases analysed. Upon arousal, all cytoplasmic and nuclear constituents restore their euthermic aspect and all morphometrical and immunocytochemical parameters exhibit the euthermic values, thereby indicating a rapid resumption of metabolic activities.

Prognostic factors in gastric cancer evaluated by using Cox regression model

OBJECTIVE

To identify the most relevant short-term predictor variables in gastric cancer removal.

EXPERIMENTAL DESIGN

A retrospective survival analysis executed by using the Cox regression model; the follow-up period is included between 18 and 90 months.

SETTING

A district general hospital surgery unit: "Divisione di Chirurgia Generale, Ospedale Civile di Urbino" (Marche, Italy).

SUBJECTS

One hundred and twenty nine consecutive patients operated for gastric cancer.

INTERVENTIONS

Surgery (total or subtotal gastrectomy).

MAIN OUTCOME MEASURE

Survival times.

RESULTS

Lymph node involvement (N) (p < 0.0001), cancer intraparietal extension (T) (p < 0.001) and the age of the patients (p < 0.05) have been recognized as significant prognostic factors.

CONCLUSIONS

Results show that the short-term prognosis largely depends on both the earliness of the diagnosis and the age of the patients.

Does lunar position influence the time of delivery? A statistical analysis

OBJECTIVE

To study the relationship between lunar position and the day of delivery; to investigate the synodic distribution of spontaneous deliveries, especially in relation to the presence of a full moon.

STUDY DESIGN

Retrospective analysis of 1248 spontaneous full-term deliveries in three-year period (36 lunar months), setted at Department of Obstetrics and Gynaecology, Civil Hospital, Fano (Marche, Italy), using circular statistics techniques.

RESULTS

A connection between the distribution of spontaneous full-term deliveries and the lunar month was found. The effect of the phases of the moon seems to be particularly relevant in multiparae and plurigravidae; in these cases, the mean day of delivery corresponds to the first or second day after the full moon.

CONCLUSIONS

In this paper the effect of lunar phases on the time of delivery is shown. This influence seems to be especially relevant in the case of multiparae and plurigravidae. Nevertheless, it is too weak to allow for prediction regarding the days with the highest frequency of deliveries.

Evaluation of factors influencing 5-fluorouracil-induced diarrhea in colorectal cancer patients. An Italian Group for the Study of Digestive Tract Cancer (GISCAD) study

Diarrhea is one of the dose-limiting toxicities for administration of fluorouracil (5FU) in patients with colorectal cancer and can result in severe morbidity and mortality. No well-defined prognostic factors influencing 5FU-associated diarrhea have been identified, which means its occurrence is unforeseeable. The aim of this study was to check whether any characteristics related to patients or chemotherapy could allow the identification of subsets of patients at higher risk of developing diarrhea while receiving a regimen containing 5FU. A logistic regression analysis was performed with age, sex, site of primary tumor, presence of primary tumor, presence of colostomy, time since surgery, number of courses of chemotherapy, diarrhea in previous courses, season of treatment, and chemotherapeutic regimens used as model parameters to predict occurrence of diarrhea in 258 colorectal cancer patients receiving a 5FU-containing regimen. Presence of primary tumor (P = 0.004), previous episodes of chemotherapy-related diarrhea (P = 0.00005) and summer season (P = 0.014) were found to be significant risk factors for developing diarrhea. The other variables examined, such as age, sex, chemotherapeutic regimen, site of primary tumor, presence of colostomy, and time since surgery, were not significantly correlated to diarrhea. Chemotherapeutic regimen was the only parameter that allowed prediction of the severity of diarrhea: 5FU/6S-leucovorin/interferon caused more severe diarrhea, followed by 5FU/leucovorin weekly. Although the analysis of these clinical features does not seem to allow the definition of a well-defined subset of colorectal cancer patients at higher risk of 5FU-induced diarrhea, it can be recommended that patients with primary tumor, or who have experienced diarrhea in earlier courses of chemotherapy or are receiving treatment in summer should be carefully monitored, especially in the first cycles.

[Incidence of lunar position in the distribution of deliveries. A statistical analysis]

OBJECTIVE

To point out the influence of the lunar position on the distribution of deliveries.

METHODS

We examined all the full-term spontaneous deliveries that occurred at the Civil Hospital in Fano (March) throughout 24 synodic months in a 2-year period (1993-1994). In order to perform the statistical analysis, each delivery was considered as a single measure. We used techniques of circular statistics to execute data analysis.

RESULTS

A significant relationship between lunar position and distribution of deliveries was pointed out in multigravidae (in detail, the deliveries resulted clustered around the full moon phase). On the contrary, no significant relation was observed in primigravidae.

CONCLUSIONS

The observed results evidence a significant influence of the position of the moon on the distribution of deliveries, especially in multigravidae.