Tumorigenicity study in Syrian hamsters fed areca nut together with nitrite

In order to evaluate the effect of concurrent administrationof areca nut and sodium nitrite, a long-term feeding study wasconducted with 120 Syrian hamsters. The animals were dividedinto four treatment groups, each consisting of 15 males and15 females, and received 2 g/kg diet of sodium nitrite (groupI), 20 g/kg diet of powdered areca nut (group II), 2 g/kg dietof sodium nitrite plus 20 g/kg diet of areca nut (group III)or powdered diet only (group IV) throughout their lifetime.Urine samples from all groups were analysed for N-nitrosonipecoticacid (NNIP), a major urinary metabolite of areca-nut-derivednitrosamines. NNIP was only detected in the urine of hamstersfed nitrite plus areca nut (concentration: 1.9±0.9 ng/mlurine), indicating that areca nut alkaloids underwent in vivonitrosation to form arecanut-specific nitrosamines. The totaltumour response was not significantly elevated in groups IIand III. Hamsters of group III had a markedly, but also insignificantlyhigher frequency of malignant tumours than those of the othergroups, with a statistically significant increase in malignantlymphomas in the males. Although limited by the low number ofanimals per group, these results indicate that exposure to nitritetogether with areca nut constituents appears to enhance therisk of developing malignancies.     

Treatment of patients with advanced colorectal cancer with cisplatin, 5-fluorouracil, and leucovorin

Based on in vitro studies that have demonstrated synergy between 5-fluorouracil (5-FU), leucovorin (LV), and cisplatin (CDDP) against human colon cancer cell lines, a clinical trial was initiated to determine the effects of this combination in patients with advanced unresectable colorectal carcinoma. Fifty-nine patients were enrolled in the study and 12 of them had received prior conventional 5-FU chemotherapy. Treatment consisted of 4 weekly courses of high-dose LV (200 mg/m2) administered by intravenous (IV) bolus, followed by 5-FU (550 mg/m2) and CDDP (20 mg/m2) each administered as a 2-hour infusion on 4 consecutive days. After a median of 5.5 treatment cycles, objective tumor response was seen in 20 of 59 patients (34%) (this included 3 complete remissions). The response rate in the 47 previously untreated patients was 38% (95% confidence limits, 26% to 53%). Stable disease occurred in 16 (27%) patients, whereas the tumor progressed in 23 (39%) patients. The median survival time was 11.5 months, with 15% of the patients alive at 2 years. The regimen was well tolerated and the primary side effects were mild and reversible gastrointestinal symptoms and myelosuppression. There was no episode of life-threatening toxicity. Eastern Cooperative Oncology Group (ECOG) Grade III adverse reactions that required 25% dose reductions occurred in only 14% of the patients. The results of this trial suggest that 5-FU, LV, and CDDP is an active, safe, and well-tolerated combination regimen in patients with advanced colorectal cancer.     

Ecologic Study of Lung Cancer Risk Factors in the U.S. and Japan, with Special Reference to Smoking and Diet

Lung cancer mortality rates among United States and Japanese males were compared and related to smoking and dietary data. Mortality rates increased from 1950 to 1985 in both countries, but the absolute values are consistently lower in Japan (38.2 deaths/100,000 in 1985) than in the U.S. (72.2/100,000). The proportion of smokers is higher in Japan than in the U.S. since 1955. Japanese males start smoking considerably later than U.S. males, but smoke a higher quantity of cigarettes per day. Available information on inhalation practices and yield and type of cigarettes smoked showed no differences among the two countries large enough to account for the differences in mortality rates. Further data in this regard should he obtained. Dietary data show that fat consumption (as percentage of calories) is consistently higher in the U.S. than in Japan from 1950 (40% vs. 7.9%) through 1985 (43.5% vs. 24.5%). A linear relationship is observed between lung cancer mortality and fat intake. Our data support the hypothesis that dietary habits may modulate the carcinogenic effects of tobacco smoking.     

The orthopan tomoscintigram — a new application of emission computed tomography for facial bone scanning

The exact regional correlation of findings of facial bone scans, planar or SPECT, to dental orthopan X-ray films (OPT) is difficult because of the very different projection techniques. To improve correlative imaging in this regard a projection algorithm was developed that uses SPECT data of the skull for reconstructing an orthopan tomoscintigraphic projection. Fourteen conventional SPECT slices of the upper and lower jaws were obtained during bone scanning. All mandibular slices were superimposed resulting in a horseshoe shaped structure, which was marked by an ROI which was divided into segments. All 14 SPECT slices were then masked by this segmental ROI, thereby marking the teeth-carrying bone in all slices. The information from this horseshoe like ROI is then transformed into lines. Line by line arrangement results in an orthopan projection, the orthopan tomoscintigram. This new display allows 1:1 true scale superimposition with the X-ray OPT and markedly facilitates correlative imaging.     

Direct absolute quantification of metabolites in the human brain with in vivo localized proton spectroscopy.

The absolute concentrations of the three major brain metabolites observable by in vivo proton spectroscopy--N-acetylaspartate(NAA), creatine and phosphocreatine (Cr and PCr) and choline (Cho)--have been measured at four standardized localizations in 34 healthy volunteers by in vivo localized proton spectroscopy using an external reference sample. The results show that the concentration of Cr and PCr as observed by in vivo MRS (5-6 mmol/L) is lower than that measured by other methods. The results are concordant with the hypothesis, that the Cr and PCr resonance as observed by proton spectroscopy is due mainly to PCr, whereas Cr remains invisible by being attached to a larger molecule. It is also demonstrated, that Cr and PCr is higher in the cerebellum than in the cerebrum, whereas NAA remains constant within the margin of error (8-9 mmol/L).     

Assessment of global and regional left ventricular function and volumes with 64-slice MSCT: a comparison with 2D echocardiography.

BACKGROUND: In patients with coronary artery disease (CAD), LV function and volumes are important parameters for long-term prognosis. Multislice computed tomography (MSCT) allows noninvasive assessment of the coronary arteries, but the accuracy of 64-slice MSCT for the assessment of left ventricular (LV) volumes and function is unknown. METHODS AND RESULTS: A head-to-head comparison between 64-slice MSCT and 2-dimensional (2D) echocardiography was performed in 40 patients with known or suspected CAD. The LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV) were determined and the LV ejection fraction (LVEF) was derived. Regional wall motion was assessed visually using a 17-segment model. A 3-point scoring system was used to assign to each segment a wall motion score: 1 = normokinesia, 2 = hypokinesia, 3 = akinesia or dyskinesia. Two-dimensional echocardiography served as the gold standard. MSCT agreed well with 2D echocardiography for assessment of LVEDV (r = 0.97; p < .0001) and LVESV (r = 0.98; p < .0001). An excellent correlation between MSCT and 2D echocardiography was shown for the evaluation of LVEF (r = 0.91; p < .0001). Agreement for the assessment of regional wall motion was excellent (96%, kappa = 0.82). CONCLUSIONS: An accurate assessment of global and regional LV function and volumes is feasible with 64-slice MSCT.     

THE NATIONAL BIRTH CENTER STUDY Part II—Intrapartum and Immediate Postpartum and Neonatal Care

Part II of a three-part report of the National Birth Center Study describes care provided to 11,814 women and their newborns during and after labor and delivery until they were transferred or discharged from the birth centers. There were few low birth weight or preterm or postterm births, but more macrosomic babies than among all U.S. births during the same time period. Certified nurse-midwives provided most of the intrapartum care, which is described in the context of medically recommended standards and data that describe care provided to low-risk women giving birth in U.S. hospitals. Birth center care deviated from typical hospital care in several ways. Birth center clients were much less likely to receive central nervous system depressants, anesthesia, continuous electronic fetal monitoring, induction and/or augmentation of labor, intravenous infusions, amniotomies, or episiotomies, and they had relatively few vaginal examinations. They were more likely to eat solid food during labor and to take showers and/or baths Nulliparity was strongly associated with longer first stage labors and longer labor was associated with more frequent use of many kinds of interventions. Infant birth weight, mother's position during delivery, and forceps- or vacuum-assisted deliveries are examined in relation to episiotomies and lacerations and tears.