Arterial spin-labeled perfusion imaging reflects vascular density in nonfunctioning pituitary macroadenomas

BACKGROUND AND PURPOSE

Angiogenesis is very important in clinical features of pituitary adenomas. We investigated the relationship between the blood flow of nonfunctioning pituitary macroadenomas measured by arterial spin-labeled perfusion imaging and the microvessel attenuation of the tissue.

MATERIALS AND METHODS

Conventional MR imaging with contrast-enhanced T1WI and arterial spin-labeled perfusion imaging were performed before surgery in 11 consecutive patients with nonfunctioning pituitary macroadenomas. ROIs were drawn on the tumors, and the degrees of enhancement were calculated by dividing the signal intensity on the contrast-enhanced T1WI by that on the nonenhanced TIWI. As an index of tumor perfusion, a quantitative analysis was performed by using normalized tumor blood flow values calculated by dividing the mean value of the tumor region of interest by the mean region of interest values in the 2 cerebellar hemispheres. The relative microvessel attenuation was determined as the total microvessel wall area divided by the entire tissue area on CD-31-stained specimens. The degree of enhancement and the normalized tumor blood flow values were compared with relative microvessel attenuation. Additionally, intra- and postoperative tumor hemorrhages were visually graded.

RESULTS

The degree of enhancement was not correlated with relative microvessel attenuation. Statistically significant correlations were observed between normalized tumor blood flow values and relative microvessel attenuation (P < .05). At surgery, 3 cases were visually determined to be hypervascular tumors, and 1 of these cases had symptomatic postoperative hemorrhage. A statistically significant difference in normalized tumor blood flow values was observed visually between the intraoperative hypovascular and hypervascular groups (P < .05).

CONCLUSIONS

Arterial spin-labeled perfusion imaging reflects the vascular density of nonfunctioning pituitary macroadenomas, which may be useful in the preoperative prediction of intra- and postoperative tumor hemorrhage.

Complete remission of primary retroperitoneal transitional cell carcinoma after radiotherapy and oral chemotherapy: a case report

Primary retroperitoneal transitional cell carcinomas (TCCs) are extremely rare neoplasms for which prognosis is very poor. We present a case that underwent complete remission after radiotherapy and concurrent oral chemotherapy. A 68-year-old woman presented with acute onset of bloody stool. Urgent colonoscopy only detected haemorrhoids. Subsequent abdominal ultrasonography revealed a mass of 7 cm in maximal diameter in the left iliac fossa. Laparotomy disclosed a retroperitoneal mass that could not be dissected and therefore only incision biopsy was performed. After a final diagnosis of primary retroperitoneal TCC, chemotherapy with tegafur-uracil (UFT) was initiated but was not effective. Subsequently, radiotherapy was initiated concurrently with UFT at a total dose of 50 Gy in 25 fractions. At 20 months after radiotherapy, the tumour seemed to have completely remitted. At the last follow-up, ten years from radiotherapy, computed tomography revealed no recurrence. We identified only three single case reports regarding primary retroperitoneal TCC over the last five decades. All patients died from the tumour 8-24 months after diagnosis or treatment. Based on the success of our case, radiotherapy with concurrent oral chemotherapy should be considered as an option for unresected cases.

Changes in snuff and smoking habits in Swedish pregnant women and risk for small for gestational age births

OBJECTIVE

To examine associations between antenatal exposure to Swedish oral moist snuff (which includes essentially only nicotine) and to smoking and risks of small-for-gestational-age (SGA) births and to compare risks among women who stopped or continued using snuff or smoking during pregnancy.

DESIGN

Population-based cohort study.

SETTING

Sweden.

POPULATION

All live singleton births in Sweden 1999-2010.

METHODS

Odds ratios (OR) with 95% confidence intervals (CI) were calculated using multiple logistic regression analysis.

MAIN OUTCOME MEASURES

SGA birth, also stratified into preterm (≤36 weeks of gestation) and term (≥37 weeks of gestation) SGA births.

RESULTS

Compared with non-tobacco users in early pregnancy, snuff users and above all smokers in early pregnancy had increased risks of SGA births: adjusted ORs (95% CI) were 1.26 (1.09-1.46) and 2.55 (2.43-2.67), respectively). Snuff use had, if anything, a stronger association with preterm SGA than term SGA, whereas the opposite was true for smoking. Compared with non-tobacco users, women who stopped using snuff before their first visit to antenatal care had no increased risks of preterm or term SGA, and women who stopped using snuff later during pregnancy had no increased risk of term SGA. Smoking cessation early in pregnancy was associated with a larger reduction in risk than smoking cessation later in pregnancy.

CONCLUSIONS

As both smoking and snuff use influence risk of SGA, both nicotine but above all tobacco combustion products are involved in the mechanisms by which maternal smoking increases the risk of SGA.

α1-Adrenoceptor Subtypes in the Rat Ventricular Muscle

Scatchard analyses of [3H]prazosin binding in rat ventricular muscle membranes showed biphasic curves, which identified α1High- and α1Low-affinity sites. The α1High-affinity site was completely inhibited by 1 μm phenoxybenzamine. The displacement potencies of α1-adrenergic antagonists were characterized by [3H]prazosin binding to α1High. and α1Low-affinity sites in the absence and presence of 1 μm phenoxybenzamine. The affinities of most chemicals for α1Low-affinity sites were significantly lower than those for α1High-affinity sites, but WB-4101 (2-(2,6-dimethoxy-phenoxyethyl)aminomethyl-1,4-benzodioxane), arotinolol, cinanserin, nifedipine, and p-aminoclonidine had the same affinities for both α1Low- and α1High-affinity sites. These results show that two α1-adrenoceptor subtypes, α1High- and α1Low-affinity, are present in the rat heart, and that there are physical variations in α1-adrenoceptor binding sites, based on their selectivity to antagonists.

α1-Adrenoceptor Subtypes in Bovine Prostate

The object of this study was to examine the existence and characteristics of α1-adrenoceptor subtypes in the bovine prostate using the radioligand binding assay method. [3H]Prazosin was used as the radioligand and its binding sites in bovine prostate were classified into two subtypes. One subtype showed a high affinity (α1High, Kd: 101·1 Pm and Bmax: 11·8 fmol (mg protein)−1) and the other had a low affinity (α1Low, Kd: 3371·4 Pm and Bmax: 50·5 fmol (mg protein)−1). Although the same pKi values of clorethylclonidine, p-aminoclonidine, benoxathian and dibenamine to both α1High and α1  Low binding sites in bovine prostate tissue were observed, other α1 antagonists used in this study had different pKi values for the two α1-adrenoceptor subtypes. The existence and binding characteristics of α1-adrenoceptor subtypes in bovine prostate were clarified. It is possible that agents selective for one site may contribute to the development of better drugs for the treatment of bladder outlet obstructions of men with benign prostatic hyperplasia.