Measurement of the analyzing power in p-->d-->(p p)n with a fast forward 1S0 proton pair

A measurement of the analyzing power A(y) of the p-->d--> (p p) + n reaction was carried out at the ANKE spectrometer at COSY at beam energies of 0.5 and 0.8 GeV by detection of a fast forward proton pair of small excitation energy E(pp) < 3 MeV. The S-wave dominance in the fast diproton is experimentally demonstrated in this reaction. While at T(p) = 0.8 GeV the measured analyzing power almost vanishes, it rises to nearly unity at T(p) = 0.5 GeV for neutrons emitted at theta(c.m.)(n) = 167 degrees. The results are compared with a model taking into account one-nucleon exchange, single scattering, and Delta(1232) excitation in the intermediate state. The model describes fairly well the unpolarized cross section obtained earlier and the analyzing power at 0.8 GeV; it fails to reproduce A(y) at 0.5 GeV.

Motion correction in PET/CT

Motion in PET/CT leads to artifacts in the reconstructed PET images due to the different acquisition times of positron emission tomography and computed tomography. The effect of motion on cardiac PET/CT images is evaluated in this study and a novel approach for motion correction based on optical flow methods is outlined. The Lukas-Kanade optical flow algorithm is used to calculate the motion vector field on both simulated phantom data as well as measured human PET data. The motion of the myocardium is corrected by non-linear registration techniques and results are compared to uncorrected images.

The effect of wool vs. cotton head covering and length of stay with the mother following delivery on infant temperature

Rectal temperature of 126 term infants was measured on admission to the nursery following variable periods of stay with the mother in the delivery room. Fifty-nine infants who wore woolen hats after delivery had higher rectal temperature than 67 infants whose head was covered by loosely applied cotton diapers (36.5+/-0.5 degrees C vs. 36.3+/-0.5 degrees C, respectively; p=0.03). Among them there were fewer infants who were admitted with rectal temperature 36 degrees C (12 vs. 26, respectively; p=0.03). In multiple regression analyses accounting for head covering with woolen hats, birth weight, gender, delivery room temperature and length of stay with the mother, only birth weight and head covering with woolen hats were significantly associated with rectal temperature at arrival in the nursery (p=0.002 and 0.03, respectively), and only head covering with cotton diapers was significantly associated with rectal temperature 36 degrees C (p=0.03). Our data imply that covering heads of term newborns with simple woolen hats may reduce or prevent heat loss following delivery, and that adequate warming of infants is achieved during prolonged stay with the mother.

Effects of transcranial direct current stimulation over the human motor cortex on corticospinal and transcallosal excitability

Weak transcranial direct current stimulation (tDCS) can induce long lasting changes in cortical excitability. In the present study we asked whether tDCS applied to the left primary motor cortex (M1) also produces aftereffects distant from the site of the stimulating electrodes. We therefore tested corticospinal excitability in the left and the right M1 and transcallosal excitability between the two cortices using transcranial magnetic stimulation (TMS) before and after applying tDCS. Eight healthy subjects received 10 min of anodal or cathodal tDCS (1 mA) to the left M1. We examined the amplitude of contralateral motor evoked potentials (MEPs) and the onset latency and duration of transcallosal inhibition with single pulse TMS. MEPs evoked from the tDCS stimulated (left) M1 were increased by 32% after anodal and decreased by 27% after cathodal tDCS, while transcallosal inhibition evoked from the left M1 remained unchanged. The effect on MEPs evoked from the left M1 lasted longer for cathodal than for anodal tDCS. MEPs evoked from the right M1 were unchanged whilst the duration of transcallosal inhibition evoked from the right M1 was shortened after cathodal tDCS and prolonged after anodal tDCS. The duration of transcallosal inhibition returned to control values before the effect on the MEPs from the left M1 had recovered. These findings are compatible with the idea that tDCS-induced aftereffects in the cortical motor system are limited to the stimulated hemisphere, and that tDCS not only affects corticospinal circuits involved in producing MEPs but also inhibitory interneurons mediating transcallosal inhibition from the contralateral hemisphere.

Pharmacological modulation of cortical excitability shifts induced by transcranial direct current stimulation in humans

Transcranial direct current stimulation (tDCS) of the human motor cortex results in polarity-specific shifts of cortical excitability during and after stimulation. Anodal tDCS enhances and cathodal stimulation reduces excitability. Animal experiments have demonstrated that the effect of anodal tDCS is caused by neuronal depolarisation, while cathodal tDCS hyperpolarises cortical neurones. However, not much is known about the ion channels and receptors involved in these effects. Thus, the impact of the sodium channel blocker carbamazepine, the calcium channel blocker flunarizine and the NMDA receptor antagonist dextromethorphane on tDCS-elicited motor cortical excitability changes of healthy human subjects were tested. tDCS-protocols inducing excitability alterations (1) only during tDCS and (2) eliciting long-lasting after-effects were applied after drug administration. Carbamazepine selectively eliminated the excitability enhancement induced by anodal stimulation during and after tDCS. Flunarizine resulted in similar changes. Antagonising NMDA receptors did not alter current-generated excitability changes during a short stimulation, which elicits no after-effects, but prevented the induction of long-lasting after-effects independent of their direction. These results suggest that, like in other animals, cortical excitability shifts induced during tDCS in humans also depend on membrane polarisation, thus modulating the conductance of sodium and calcium channels. Moreover, they suggest that the after-effects may be NMDA receptor dependent. Since NMDA receptors are involved in neuroplastic changes, the results suggest a possible application of tDCS in the modulation or induction of these processes in a clinical setting. The selective elimination of tDCS-driven excitability enhancements by carbamazepine proposes a role for this drug in focussing the effects of cathodal tDCS, which may have important future clinical applications.

a+0 (980)-resonance production in pp-->dK+K-0 reactions close to threshold

The reaction pp-->dK+K(-)0 has been investigated at an excess energy of Q=46 MeV above the K+K(-)0 threshold with ANKE at the cooler synchrotron COSY-Jülich. From the detected coincident dK(+) pairs, about 1000 events with a missing K(-)0 were identified, corresponding to a total cross section of sigma(pp-->dK+K(-)0)=[38+/-2(stat)+/-14(syst)] nb. Invariant-mass and angular distributions have been jointly analyzed and reveal s-wave dominance between the two kaons, accompanied by a p wave between the deuteron and the kaon system. This is interpreted in terms of a(+)0 (980)-resonance production.

The effect of bowel resection on survival in advanced epithelial ovarian cancer

OBJECTIVE

FIGO stage III ovarian cancer is further categorized according to the size of tumor, but not according to the organs affected. In this study we evaluated the outcome of patients with and without macroscopic bowel involvement in stage III ovarian cancer.

METHODS

This retrospective study analyzed the outcome of 194 ovarian cancer patients with FIGO III with and without bowel involvement who were operated on in our institution between 1985 and 1994.

RESULTS

The study demonstrated that maximum tumor reduction without remaining macroscopic cancer offered the best overall survival times in FIGO III ovarian cancer patients. However, whenever the bowel was involved, even maximum bowel resections did not prolong survival compared to patients with remaining tumor after surgery.

CONCLUSIONS

This retrospective study demonstrated that bowel involvement in ovarian cancer had a bad prognosis and that survival in these patients could not substantially be prolonged when the affected parts of bowel were resected. To further substantiate these findings, future studies on advanced ovarian cancer should differentiate between patients with and without bowel involvement.

Epithelial cells in bone marrow of breast cancer patients at time of primary surgery: clinical outcome during long-term follow-up

PURPOSE

To evaluate the detection of epithelial cells in bone marrow of breast cancer patients as an indicator of metastatic disease.

PATIENTS AND METHODS

Between 1989 and 1994, bone marrow biopsies were performed on 393 breast cancer patients during primary surgery. Specimens were stained immunocytochemically for epithelial cells expressing cytokeratins or the epithelial membrane antigen. The long-term outcomes of these patients were analyzed in this study.

RESULTS

In 166 of 393 patients, epithelial cells were found in bone marrow (BM) aspirates. These patients were designated BM+. The rate of tumor recurrence or cancer-related death was significantly higher in BM+ patients than in BM- patients. Multivariate analysis using the Cox regression model revealed BM status as a prognostic parameter independent of tumor size and axillary lymph node status. However, tumor size and axillary lymph node status were clearly superior prognostic parameters.

CONCLUSION

Disseminated epithelial cells in BM are associated with poor clinical outcome in breast cancer patients. However, the presence of these cells is not a sufficient parameter to predict growing metastases in the majority of patients, suggesting that epithelial cells in the BM of breast cancer patients at the time of surgery have limited metastatic potential. The role of these cells needs to be further evaluated.

Validity of an ELISA for N-acetyltransferase-2 (NAT2) phenotyping

A competitive antigen ELISA was previously developed for NAT2 phenotyping, using caffeine as the probe drug. The ELISA phenotypes by measuring the ratio of 5-acetamido-6-amino-3-methyluracil (AAMU) and 1-methylxanthine (1X) after transformation of 5-acetamido-6-formylamino-3-methyluracil (AFMU) to AAMU, in contrast to capillary electrophoresis high-pressure liquid chromatography (HPLC) which phenotype by measuring the AFMU/1X ratio. The ELISA phenotyping was previously determined in 30 samples and correlated well with phenotypes determined by capillary electrophoresis (29/30). The correlation was extended with the standard HPLC methodology by expanding the data set by 146 in order to test the validity of the ELISA methodology. The correlation with HPLC in this larger sample size was 96%; whereas the correlation between the two methods for determination of 1X was high (r(2)=0.90), that for determination of AAMU by ELISA and AFMU by HPLC was low (r(2)=0.53). The poor correlation between the two methodologies could not be attributed to the age of urine samples, nor to a significant decomposition of AFMU in the body prior to collection of the urine sample. The addition of a simple caffeine metabolite extraction method, originally developed for HPLC analysis of metabolites, to the ELISA phenotyping protocol produced a methodology with absolute correlation to the standard HPLC method.

Phase I and pharmacokinetic study of hepatic arterial infusion with oxaliplatin in combination with folinic acid and 5-fluorouracil in patients with hepatic metastases from colorectal cancer

BACKGROUND

To determine dose-limiting toxicity (DLT), maximum tolerated dose (MTD), and pharmacokinetics (PK) of oxaliplatin administered as hepatic arterial infusion.

PATIENTS AND METHODS

Patients with isolated hepatic metastases from colorectal cancer were treated every three weeks with increasing doses of oxaliplatin (4 hours; starting dose 25 mg/m2, escalation in steps of 25 mg/m2) in combination with folinic acid (1 hour, 200 mg/m2) and 5-fluorouracil (2 hour, 600 mg/m2).

RESULTS

Twenty-one patients (median age, 61 years) have been entered all of whom are fully evaluable. The DLT has been observed at dose level 6, i.e., at 150 mg/m2/cycle and consisted of leucopenia, obliteration of the hepatic artery, and acute pancreatitis. Overall, toxicity mainly consisted of nausea/vomiting (16 of 21 patients), anemia (16 of 21), upper abdominal pain (15 of 21), sensory neuropathy (10 of 21), diarrhea (9 of 21), and thrombocytopenia (9 of 21). The mean PK parameters were: terminal half-life of ultrafiltrable platin, 17.75 +/- 9.29 hours; renal elimination, 48.7% +/- 14.1% of the applied dose; renal clearance 135.55 +/- 45.32 ml/min. The mean area under the plasma-concentration curve (AUC) increased linearly from 3.22 +/- 0.61 microg x h/ml to 18.45 +/- 8.90 microg x h/ml through the first five dose levels (P = 0.0004). Ten of eighteen evaluable patients achieved a complete or partial response (59%).

CONCLUSIONS

The recommended dose for phase II studies is 125 mg/m2 oxaliplatin.

Growth regulation effects of gonadotropin induced steroidogenic response in human ovarian cancer

BACKGROUND

Despite a substantial body of epidemiological evidence, there is only a limited indication that gonadotropins and steroids have growth regulating functions in ovarian cancer. To elucidate the role of gonadotropins in regulating steroid metabolism in human ovarian cancer, we analyzed the modulation of estradiol secretion by FSH and hCG and the gonadotropic regulation of hCG secretion in vitro. Furthermore, we analyzed estradiol and hCG levels in serum and cyst fluids of patients with ovarian cancer.

MATERIALS AND METHODS

OVCAR3 cells were incubated with estradiol (1, 5, 10 nM), FSH (100 microg/L) and hCG (10, 25 microg/L). Growth stimulation was evaluated by MTT assay. Estradiol was measured in the supernatant after incubation with hCG and FSH, while hCG was measured after FSH incubation. FSH, estradiol and hCG levels were measured in serum and cyst fluids of patients with ovarian cancer.

RESULTS

OVCAR3 cells responded to hCG and FSH by increased estradiol secretion (p<0.001), while estradiol led to a dose-dependent stimulation of cell growth (p<0.05). 100 microg/L FSH led to a 75% decrease of hCG secretion (p<0.001).

CONCLUSION

Gonadotropins stimulate estradiol secretion in ovarian cancer cells and modulate steroid dependent growth stimulation. FSH modulates hCG related growth stimulation in ovarian cancer. These results were supported by in vivo measurements in ovarian cancer patients.

[Mammography/stereotactically controlled vacuum excisional biopsy. Interventional methods in breast diagnosis]

As well as in the complementary mamma diagnosis (clinical examination, mammography, sonography) including the dynamic MRI and the mammography screening projects the interventional methods like mammographically/stereotactically guided vacuumbiopsy/excisional biopsy are established methods to avoid unnecessary open operations and they are integrated in the clinical routine. By using strict criterias it is a way to improve the specificity and the negative predictive value in the mamma diagnosis. In addition the interventional methods requires less costs, less time and reduces the morbidity in comparison to an open operation.