Vascularisation of benign and malignant thyroid nodules: CD US evaluation.

PURPOSE: Frequency encoded Doppler ultrasound (DUS) imaging has allowed identification of flow in thyroid tumours, but its role in evaluation of thyroid nodules for malignancy has not been accurately defined. We wanted to investigate the possible role of DUS in differentiation of benign and malignant nodules. MATERIALS AND METHODS: DUS and spectral parameters were analysed in 50 benign and 20 malignant thyroid nodules. The following patterns of vascularity were identified: pattern 0--no visible flow; pattern 1--minimal internal flow without a peripheral ring; pattern 2--peripheral ring of flow but minimal or no internal flow; pattern 3--peripheral ring of flow and a small-to moderate amount of internal flow; pattern 4--extensive internal flow with or without a peripheral ring. Peak systolic velocity (PSV) and end diastolic velocity (EDV) was measured and resistance index (RI) was calculated. RESULTS: Significantly more benign nodules had vascularisation patterns 1.2 and 3. Significantly more malignant nodules had vascularisation patterns 3 and 4, and only pattern 4. EDV was significantly lower in malignant than in benign nodules (6.06 +/- 4 cm/sec vs. 13.01 +/- 8.74 cm/sec). RI was significantly higher in malignant than in benign thyroid nodules (0.75 +/- 0.08 vs. 0.56 +/- 0.09). For RI > or = 0.70: 80% sensitivity, 92% specificity, 80% positive predictive value, 92% negative predictive value, and 88.6 % accuracy, were calculated in characterising malignant thyroid nodules. CONCLUSION: We believe that internal flow without or with minimal peripheral flow on DUS and RI > or = 0.70 can be used to distinguish between malignant and benign thyroid nodules fairly reliably. Nodules with prevailing peripheral vascularisation and minimal or no internal vascularisation, and RI below 0.70 are probably benign.

Determinants of reduced bone mineral density and increased bone turnover after kidney transplantation: cross-sectional study.

AIM: To analyze bone metabolism and the risk factors of bone loss in kidney transplant recipients. METHODS: The bone mineral density (BMD) of the lumbar spine, femoral neck, and radius was determined by dual-energy X-ray absorptiometry in 52 patients 8 days to 228 months after kidney transplantation. Total and bone alkaline phosphatase (BAP), osteocalcin, procollagen, type I collagen telopeptide, collagen cross links, calcium, intact parathyroid hormone (iPTH), and creatinine were measured in all patients. RESULTS: The BMD of the spine and femoral neck was reduced in 57%, and of the radius in 72% of the patients. Reduced BMD was associated with significantly increased levels of iPTH, osteocalcin, and procollagen. Dialysis duration negatively correlated with the radius BMD in all patients and the femoral neck BMD in women. No relationship between BMD and length of post-transplantation time, age, cumulative steroid dose, or serum creatinine level was established. All biochemical parameters negatively correlated with the spine BMD, but not with the BMD of the femoral neck and radius. The correlation between BAP and telopeptide and length of post-transplantation time was also negative. No difference in the incidence of osteopenia was found between genders. CONCLUSION: Osteopenia/osteoporosis and increased bone turnover were present in more than a half of the kidney transplant recipients. Reduced BMD was associated with enhanced bone remodeling, primarily mediated by PTH hypersecretion. The length of post-transplantation period, cumulative steroid dose, gender, and age could not be identified as risk factors of reduced BMD.

Neural growth factor inhibits the growth of rat egg-cylinders cultured in vitro.

Rat egg-cylinders at the primitive streak stage were grown in modified organ culture for 2 weeks using a chemically defined medium. Differentiation of the epidermis and cartilage was comparable to that in fully serum-supplemented medium, whereas neuroblasts were very scarce. In explants treated either with bovine serum albumin or transferrin, neuroblasts were observed, whereas the addition of NGF did not improve neuroblast differentiation. On the contrary, NGF impaired growth and tissue differentiation when compared with explants grown in serum-free medium.

Syndrome of inappropriate secretion of anti-diuretic hormone (SIADH) produced by an adenocarcinoma of the colon. Report of one case.

It is described a patient with all classical features of SIADH, and elevated levels of urinary ADH which was most probably produced by a colon carcinoma. It is proposed that all indistinct hyponatremias be thoroughly analysed and that urinary ADH be tentatively considered as a tumor marker for colon carcinoma.

Reduction of total and free triiodothyronine in serum after abortion.

The effect of abortion on serum concentration of thyroid hormones was studied in 11 normal women. After abortion, serum free and total T3 fall significantly, while free and total reverse T3, T4, TSH and TBG in serum show no significant variation. These data suggest that surgical stress in normal subjects may only influence 5'-deiodinase activity, and that the peripheral conversion of T4 to active T3 and inactive rT3 are controlled by different mechanisms.

Reduced active thyroid hormone levels after delivery.

The effect of delivery on the serum concentration of thyroid hormones was studied in 25 euthyroid women. After delivery serum free and total T3 and T4 fell transiently with a simultaneous increase in reverse T3 while serum TSH and thyroxine binding globulin (TBG) concentrations showed no significant variation. These data suggest that i) similar to what happens in other stressful situations, delivery influences peripheral T4 metabolism, and ii) an elevation of TBG in serum in the early puerperium does not prevent these changes.

Similar serum concentrations of thyroid hormones in two geographically separate populations on disparate iodine intake.

Serum thyroid hormones were measured in Montreal, Canada (urinary iodine 446 +/- 164 micrograms/day) and Zagreb, Yugoslavia (urinary iodine 108 +/- 32 microgram/day). The serum concentrations of thyroxine and triiodothyronine in the two populations were almost identical. We conclude that dietary iodine, within accepted normal limits, is not a factor in determining serum thyroid hormone levels. The wide differences in reported serum triiodothyronine concentrations are related to methodological problems.