Detectability of liver metastases in malignant melanoma: prospective comparison of magnetic resonance imaging and positron emission tomography

PURPOSE: We evaluated the diagnostic accuracy of magnetic resonance imaging (MRI) and positron emission tomography (PET) for detection of liver metastases in malignant melanoma. MATERIAL AND METHODS: Thirty-five patients with 39 combined unenhanced MRI and fluorine-18 deoxyglucose (F-18 FDG) PET scans were prospectively studied. In discordant imaging findings final diagnosis was proven by clinical follow-up >6 months and demonstration of progressive liver metastases by at least one imaging method. Sensitivities and specificities were compared and the influence of lesion size and melanin content on diagnostic accuracy was determined. RESULTS: MRI and PET were concordantly negative for presence and number of liver metastases in 28 patients and positive in four patients. PET and MRI were false positive in one patient each. In one patient MRI showed a single metastases not seen by PET and in one patient MRI demonstrated more metastases at the first examination. In follow-up investigations MRI revealed more metastases than PET in both patients. The sensitivities for lesion detection were 47% (16/34) for PET and 100% for MRI. Lesion detectability by PET was related to lesion size (P < 0.0001) but not to melanin content. CONCLUSION: MRI is more sensitive in the detection of liver metastases in patients with malignant melanoma. Small lesions are easily missed by PET, while melanin content does not influence detectability by PET.     

High follicle-stimulating hormone levels should not necessarily lead to the exclusion of subfertile patients from treatment

OBJECTIVE: To determine ongoing pregnancy rates in subfertile patients with elevated FSH levels and regular cycles and to assess whether or not it is justified to exclude such patients from treatment on the basis of elevated FSH levels alone. DESIGN: Retrospective follow-up study. SETTING: Tertiary fertility center. PATIENT(S): One hundred twenty-two patients with normal FSH levels <10.0 IU/L, 126 with FSH between 10.0 and 15.0 IU/L, and 53 with FSH levels >15.0 IU/L, all having regular cycles and belonging to a general subfertility population. INTERVENTION(S): Follow-up. MAIN OUTCOME MEASURE(S): Overall and treatment-independent and treatment-dependent ongoing pregnancy rates and time to ongoing pregnancy. RESULT(S): Overall ongoing pregnancy rates declined from 65% in the normal FSH group to 47%, and 28% in the respective elevated FSH groups. However, when adjusting for differences in age and whether or not treatment was applied, this declining trend became inconsistent for both treatment-independent and treatment-dependent ongoing pregnancy rates. Only when FSH levels exceeded 20 IU/L was a clear fall in ongoing pregnancy rate observed, independent of age. In a Cox regression analysis, FSH seemed significantly associated with the outcome time to overall ongoing pregnancy (odds ratio = 0.94, 95% confidence interval, 0.88-0.99), but after adjusting for age and being on treatment or not this significance disappeared (odds ratio = 0.97, 95% confidence interval, 0.91-1.01). CONCLUSION(S): The contribution of FSH in the initial evaluation of subfertile couples is restricted to counseling patients on the probability of having lower chances of conceiving. It does not seem justified to exclude patients with normal regular cycles from treatment on the basis of the FSH value alone.     

Near infrared spectroscopy in the diagnosis of chronic exertional compartment syndrome

BACKGROUND: Patients with chronic exertional compartment syndrome (CECS) experience pain during exercise. An abnormal increase in intracompartmental pressure (ICP) leads to impaired local tissue perfusion resulting in ischemia and pain. At cessation of exercise, pain subsides. Diagnosis is confirmed through postexercise ICP. Near infrared spectroscopy (NIRS) can measure tissue oxygen saturation (StO(2)) noninvasively. HYPOTHESIS: NIRS can diagnose CECS by showing tissue deoxygenation. STUDY DESIGN: Prospective, nonrandomized clinical trial. METHOD: Volunteers completed a standardized exercise protocol. Those suspected of CECS did so preoperatively and postoperatively. StO(2) and ICP were monitored. Data were compared between volunteers and patients and prefasciotomy and postfasciotomy. RESULTS: Significant differences between the StO(2) values of volunteers and patients with CECS were found. Average peak exercise StO(2) value for those with CECS was lower than for the healthy (27 versus 56, P <.05). Patients showed more absolute and percentage change between baseline and peak exercise StO(2) (absolute: 60 versus 35, P <.05; percentage: 67 versus 38, P <.05). StO(2) values in legs with confirmed CECS returned to normal range postfasciotomy. All changes differed significantly with preoperative values. CONCLUSION: StO(2) can distinguish healthy from diseased legs. This study provides evidence supporting NIRS as a noninvasive, painless alternative to ICP in the diagnosis of CECS.     

Current smoking at menopause rather than duration determines the onset of natural menopause

BACKGROUND: Smoking has frequently been associated with early menopause. However, studies of this association have been inconclusive with regard to duration and intensity of smoking. A major problem in analyzing the effect of smoking duration on menopausal age is that both exposure and outcome are age-dependent. METHODS: We calculated age-specific rates for categories of smoking duration and subsequently computed the rate ratios for occurrence of menopause. We were thus able to model the effect of smoking duration on 2 time scales without assumptions of linearity. We used data from a Dutch population-based cohort comprising 5544 women age 49-70 years who had experienced natural menopause. RESULTS: The rate ratio (RR) for occurrence of menopause was increased in women who smoked in the year of menopause (RR = 1.41; 95% confidence interval = 1.32-1.50). The rate ratio of former smokers was similar to women who never smoked (0.95; 0.89-1.02). Prolonged exposure of smoking did not materially affect the risk of menopause, although the daily number of cigarettes currently smoked could increase the risk. CONCLUSION: Perimenopausal smoking is apparently more important than smoking history in explaining an earlier age of onset of menopause among women who smoke.     

A comparative study of amyloid-beta (1-42) as a cofactor for plasminogen activation by vampire bat plasminogen activator and recombinant human tissue-type plasminogen activator

The activity of both human tissue-type plasminogen activator (t-PA) and the PA from the saliva of the vampire bat, Desmodus rotundus, (DSPA) is critically dependent on the presence of a cofactor. The most efficient cofactor for both PAs is fibrin, but fibrinogen and amyloid beta peptides also have cofactor activities for human t-PA. Compared to t-PA, DSPA has a more stringent requirement for fibrin as a cofactor. The present study was undertaken to compare cofactor activities of amyloid beta 1-42 (Abeta1-42) for plasminogen activation by DSPA-alpha1 or by t-PA. The two PAs were incubated with different concentrations of glu-plasminogen, a chromogenic substrate for plasmin and 100 micro g mL (-1) of Abeta1-42, fibrinogen or fibrin as cofactor. Using the kinetic parameters directly determined from the chromogenic substrate conversion curves, we derived the relative efficacies of DSPA or t-PA in the presence of cofactor at the physiological plasminogen concentration of 2 micro M. In the presence of fibrin, the activity of DSPA was comparable to that of t-PA and 23,270-fold higher than its activity without cofactor, whereas fibrin induced only a 248-fold increase in t-PA activity. The activity of DSPA with Abeta1-42 or fibrinogen as cofactor was 485-fold lower than its activity in the presence of fibrin, while for t-PA this difference was only 26-fold. The much lower activity of DSPA as compared to t-PA with Abeta1-42 or fibrinogen might lead to fewer side effects when used for the thrombolytic therapy of stroke.     

Epidemiology in conflict - A call to arms

In this first special theme issue, Emerging Themes in Epidemiology publishes a collection of articles on the theme of Epidemiology in conflict. Violent conflict is an issue of great sensitivity within public health, but more structured research and reasoned discussion will allow us to better mitigate the public health impacts of war, and place the public health community in a more informed position in discussions about possible interventions in future conflicts.