Imaging of early stages of osteonecrosis of the knee

Osteonecrosis of the knee can present as a spontaneous and primary or a secondary clinical entity. The natural history of osteonecrosis follows a course of several sequential stages, and the later stages of both entities seem to be irreversible. Early diagnosis of osteonecrosis is crucial: the earlier the stage of the lesion at the time of diagnosis, the better the prognosis.Clinically, early diagnosis and treatment of osteonecrosis might prevent unnecessary surgery in cases with a concomitant degenerative meniscal tear. Early-stage osteonecrosis should be ruled out before surgery, because arthroscopy has lately been associated with osteonecrosis. Not every imaging method is equally suitable for detecting pathognomonic changes in each stage of osteonecrosis. Early-stage osteonecrosis is difficult to diagnose,because various differential diagnoses must be kept in mind. Moreover, there is a diagnostic window between the onset of symptoms and the appearance of pathognomonic changes on plain radiographs and MRI.     

Analysis of serological responses to Cryptosporidium antigen among NHANES III participants

PURPOSE: Sera from 1356 National Health and Nutrition Examination Survey (NHANES) III participants from seven primary sampling units were tested for serological responses to two Cryptosporidium antigen groups. Intensity of responses was compared by geographic area, age, sex, race/ethnicity, income, and hepatitis A seropositivity. METHODS: Cryptosporidium seropositivity for the 15/17-kDa and the 27-kDa antigen groups were defined by the intensity of the responses. Conditional and unconditional logistic regression was used to identify significant risk factors. RESULTS: Hispanics, blacks, and females had a higher seropositivity. Younger participants and those with higher income had a lower seropositivity. Being hepatitis A seropositive was strongly related to a weak serological response to the 27-kDa antigen group. Family size was unrelated to Cryptosporidium seropositivity. Significantly higher Cryptosporidium seropositivity was observed for three of the seven primary sampling units. CONCLUSIONS: This study found significant geographical differences in the occurrence and the intensity of serological response. Strong serological responses to the 15/17-kDa antigen occurred more commonly in blacks and Hispanics, individuals not having high incomes, and in older age groups.     

In vitro activity of quinolines against Plasmodium falciparum in Gabon

The assessment of drug sensitivity of Plasmodium falciparum to antimalarial drugs is of vital interest for malaria endemic regions. We conducted a follow-up study to monitor the in vitro activity of the most commonly used quinolines against fresh P. falciparum isolates in Lambaréné, Gabon by measuring schizont maturation inhibition in 2002. Mean 50% effective concentration levels for chloroquine, quinine, and mefloquine were 5.5micromol/l blood, 286nmol/l blood medium mixture (BMM), and 1.1micromol/l blood, respectively. All isolates (n=40) were found to be highly resistant to chloroquine. One isolate was resistant to mefloquine and five isolates were presenting borderline-resistance. All isolates were inhibited by quinine concentrations below the threshold of resistance (n=43).Besides the observation of an increasing number of borderline resistant isolates to mefloquine, an extremly high parasite resistance to chloroquine-still officially the first line antimalarial in Gabon-seems to be of particular concern.     

Differential effects of methylphenidate on attentional functions in children with attention-deficit/hyperactivity disorder

OBJECTIVE: To examine the effects of methylphenidate on different attentional functions and behavior in children with attention-deficit/hyperactivity disorder (ADHD). METHOD: A total of 60 ADHD children aged between 8 and 12 years completed a randomized, double-blind, placebo-controlled, within-subject crossover trial with two doses of methylphenidate (0.25 and 0.5 mg/kg body weight) and placebo. A comprehensive neuropsychological test battery was applied, including tests of alertness and sustained, focused, and divided attention as well as two executive tests, the stop-signal paradigm and a visual set-shifting task. RESULTS: A linear improvement was identified for both medication conditions in the alertness and focused and sustained attention task, but no significant improvement was found for divided attention. Quadratic trends were found for both executive tasks. Responders defined by behavior ratings did not differ from nonresponders. CONCLUSIONS: Results indicate that attentional functions are influenced differentially by methylphenidate: intensity-dimension functions are best influenced by higher doses, executive functions by moderate doses, and selectivity-dimension functions by variable doses. In addition, divergent results from behavior rating scales and from attentional paradigms emphasize that clinicians have to decide what constitutes an appropriate clinical response. A more comprehensive assessment of attention may help to find an individually optimal dose for the treatment of attentional dysfunctions.     

Only grading has independent impact on breast cancer survival after adjustment for pathological response to preoperative chemotherapy

Our objective was to determine pretreatment factors with an independent impact on survival after adjusting for response to preoperative chemotherapy and to describe parameters predictive for achieving a pathological complete remission (pCR) after preoperative chemotherapy containing an anthracycline. We performed univariate and multivariate analyses to describe the impact of the following pretreatment characteristics of 240 primary breast cancer patients who received preoperative chemotherapy containing an anthracycline at our institution on disease-free survival (DFS), distant disease-free survival (DDFS) and overall survival (OS): age, stage, clinical tumor size, clinical nodal status, grading, and expression of estrogen receptor, progesterone receptor, Her2/neu, Ki67, Bcl-2 and p53. Afterwards, the response to preoperative chemotherapy was added to the multivariate model in order to evaluate which pretreatment parameters retained their prognostic impact. In addition, univariate analysis was performed to describe pretreatment variables predictive for achieving a pCR. With a median follow-up of 6.4 years (range 0-10.4), only grading retained its independent impact on DFS, DDFS and OS [hazard ratio (HR) 1.5, 1.7 and 2.9, respectively; p<0.05] after adjusting for the strongest independent prognostic factors pathological T category at surgery (HR 1.6, 1.8 and 1.7, respectively; p<0.001) and pathological N category at surgery (HR 2.3, 2.4 and 2.1, respectively; p<0.001). Predictive factors for the achievement of pCR (p<0.05) were age under 35 years, lower stage or smaller clinical tumor size and higher expression of Bcl-2 at diagnosis. We conclude that only grading retained its independent prognostic impact on DFS, DDFS and OS after adjusting for pathological response of breast tumor and axillary lymph node metastases to preoperative chemotherapy. According to our data, it could be hypothesized that young patients with early tumor stage and small primary tumors might profit most from preoperative chemotherapy.     

Serum levels of soluble E-selectin are associated with the clinical course of metastatic disease in patients with liver metastases from breast cancer

Increasing evidence indicates that the expression of the endothelial adhesion molecule E-selectin is associated with progression and metastasis of breast cancer. Patients with liver metastases also show increased serum levels of the soluble form of E-selectin. It was our aim to compare serum levels of soluble E-selectin (sES) in such patients with the biology of the primary tumor and the course of the metastatic disease under therapy. We examined 69 patients with liver metastases from breast cancer who were selected to receive systemic tumor therapy because of progressive disease (n = 44) or newly detected liver metastases (n = 25). Serum concentrations of sES were measured before each therapy cycle using a specific ELISA. Serum concentrations of sES before the start of therapy were compared to clinical parameters and histopathological findings referring to the primary tumor. Secondly, serum levels of sES were compared to serum concentrations of the corresponding tumor markers. We observed a possible trend for certain unfavorable prognostic parameters (e.g., young women, low-graded tumors, human epidermal growth factor receptor 2 overexpression) to be related to higher serum levels of sES. Serum levels of sES were correlated with tumor marker levels in a logarithmical relation (r = 0.44, P < 0.0005). In some cases it could be demonstrated that serum levels of sES changed similarly to the course of tumor marker levels. We conclude that serum levels of sES are associated with the clinical course of liver metastases from breast cancer. Further investigations are needed to clarify if serum levels of sES may serve as tumor marker in certain clinical situations. E-selectin should be evaluated as a possible target for antimetastatic therapy studies.     

Outcome after elective labor induction in nulliparous women: a matched cohort study

OBJECTIVE: To determine whether elective induction of labor in nulliparous women is associated with changes in fetomaternal outcome when compared with labor of spontaneous onset.Study Design: All 80 labor wards in Flanders (Northern Belgium) comprised a matched cohort study. From 1996 through 1997, 7683 women with elective induced labor and 7683 women with spontaneous labor were selected according to the following criteria: nulliparity, singleton pregnancy, cephalic presentation, gestational age at the time of delivery of 266 to 287 days, and birth weight between 3000 and 4000 g. Each woman with induced labor and the corresponding woman with spontaneous labor came from the same labor ward, and they had babies of the same sex. Both groups were compared with respect to the incidence of cesarean delivery or instrument delivery and the incidence of transfer to the neonatal ward. RESULTS: Cesarean delivery (9.9% vs 6.5%), instrumental delivery (31.6% vs 29.1%), epidural analgesia (80% vs 58%), and transfer of the baby to the neonatal ward (10.7% vs 9.4%) were significantly more common (P <.01) when labor was induced electively. The difference in cesarean delivery was due to significantly more first-stage dystocia in the induced group. The difference in neonatal admission could be attributed to a higher admission rate for maternal convenience when the women had a cesarean delivery. CONCLUSION: When compared with labor of spontaneous onset, elective labor induction in nulliparous women is associated with significantly more operative deliveries. Nulliparous women should be informed about this before they submit to elective induction.     

Quantitative ultrasound for the assessment of osteopenia in preterm infants

OBJECTIVE: To evaluate the potential role of quantitative ultrasound (QUS) investigation in assessing the osteopenia of prematurity. DESIGN: QUS parameters measured at the time of discharge were related to the anthropometric characteristics and age (postnatal and gestational) of 51 (34 female and 17 male) preterm infants fed fortified human milk. METHODS: QUS evaluation was performed at the humerus (h) by measuring two parameters: ultrasound velocity (hSOS, in m/s) and bone transmission time (hBTT, in micros). A group of 43 term infants (29 female and 14 male) was also evaluated. RESULTS: In preterm infants, significant correlations were found for hSOS and hBTT vs gestational age (r=0.504, 0.477, P<0.0001), length (r=0.641, 0.594, P<0.0001) and weight (r=0.580, 0.562, P<0.0001) at birth, and length (r=0.341, 0.332, P<0.05) and weight (r=0.331, r=0.362, P<0.05) at QUS measurement. In preterm infants, both QUS parameters were negatively correlated with age (r=-0.536, P<0.0001, r=-0.443, P<0.001) and were significantly lower than in the term infants (hSOS: 1664+/-42 m/s vs 1734+/-28 m/s, P<0.0001; hBTT: 0.58+/-0.24 micros vs 1.06+/-0.15 micros, P<0.0001) even when adjusted for body length (P<0.05). In preterm infants, hSOS was also negatively correlated with postconceptional age (r=-0.322, P<0.05). CONCLUSIONS: This study suggests that bone mineral accrual is mainly determined by the development in utero, and that prematurity induces a halt in the bone development process in the early postnatal period. QUS parameters are correlated with the severity of prematurity and might therefore have clinical applications when bone maturation in early life needs to be determined.