A review of the behaviour of chondrosarcoma of bone.

Sixty-two cases of chondrosarcoma of bone were reviewed and histologically graded as low, medium or high-grade tumours. After excluding patients dead from unrelated causes or lost to follow-up, forty cases were available for ten-year follow-up and fifty-eight for five-year follow-up. The rates of survival, recurrence and metastasis were analysed according to the histological grading. Recurrence was further analysed according to the adequacy of treatment. The results were compared with those previously reported in the literature. There was a ten-year survival rate of 58 per cent. Recurrence developed in 58 per cent and was uncontrollable in 29 per cent. The recurrence rate was 87 per cent with inadequate treatment and 15 per cent with adequate treatment. Recurrences outside the limb bones usually proved uncontrollable; recurrences in the limb bones were amenable to further, and if necessary repeated, operations. High-grade chondrosarcoma had a metastatic risk of 75 per cent and eventual mortality of 88 per cent. Medium-grade chondrosarcoma had a metastatic risk of 14 per cent and a mortality of 60 per cent. Low-grade chondrosarcoma had a metastatic risk of 5 per cent and a mortality of 29 per cent.     

Pharmacokinetics and Acute Lethality of Perfluorooctanesulfonate (PFOS) to Juvenile Mallard and Northern Bobwhite

Ten-day-old mallards (Anas platyrhynchos) and northern bobwhite quail (Colinus virginianus) were fed perfluorooctanesulfonate (PFOS) in their diet for 5 days. The birds were then observed for 3 days while being given uncontaminated feed, and half of the birds were sacrificed on Day 8 of the trial. The remaining birds were maintained for an additional two weeks prior to being euthanized on Day 22 of the trial. Birds were assessed for growth, rate of feed consumption, behavior, physical injury, mortality, and gross abnormalities. Liver weight and concentrations of PFOS in blood serum and liver were also assessed. Based on the average daily intake (ADI) of PFOS calculated over the 5-day exposure period, the LD₅₀ for juvenile mallards was determined to be 150 mg PFOS/kg body weight (bw)/day, equivalent to a total cumulative dose of 750 mg PFOS/kg bw calculated over a 5-day period. For juvenile quail, the LD₅₀ based on the ADI was 61 mg PFOS/kg bw/day, equivalent to a total cumulative dose of 305 mg PFOS/kg bw. Reductions in weight gain and body weight were observed in quail from the 141 mg PFOS/kg treatment, but these measures returned to control levels by Day 22. The no-mortality dietary treatments were 70.3 and 141 mg PFOS/kg feed for quail and mallards, respectively. Both mallards and quail accumulated PFOS in blood serum and liver in a dose-dependent manner. The half-lives of PFOS in mallard blood serum and liver were estimated to be 6.86 and 17.5 days, respectively. In quail, the half-life of PFOS in liver was estimated to be 12.8 days, while the half-life of PFOS in quail blood serum could not be estimated. Concentrations of PFOS in juvenile mallard and quail liver associated with mortality are at least 50-fold greater than the single maximum PFOS concentration that has been measured in livers of avian wildlife.     

Nutrient intake in community-dwelling adolescent girls with anorexia nervosa and in healthy adolescents

BACKGROUND: Adolescence is a common time for the onset of anorexia nervosa (AN), a condition associated with long-term medical and hormonal consequences. OBJECTIVE: The objective was to compare the nutrient intakes of community-dwelling girls with AN with those of healthy adolescents and to describe the associations between specific nutrient intakes and nutritionally dependent hormones. DESIGN: Nutrient intakes in 39 community-dwelling girls with AN and 39 healthy adolescents aged 12.1-18.7 y were determined by using 4-d food records. Fasting adiponectin, leptin, ghrelin, insulin, and insulin-like growth factor I (IGF-I) concentrations were measured. Indirect calorimetry was used to assess respiratory quotient and resting energy expenditure. RESULTS: In contrast with the control group, the AN group consumed fewer calories from fats (P < 0.0001) and more from carbohydrates (P = 0.0009) and proteins (P < 0.0001). Intake of individual fat components was lower and of dietary fiber higher in the AN group. No significant between-group differences were observed in dietary intakes of calcium, zinc, and iron; however, total intake was greater in the AN group because of greater supplement use (P = 0.006, 0.02, and 0.01, respectively). The AN group had greater intakes of vitamins A, D, and K and of most of the B vitamins, and significantly more girls with AN met the Dietary Reference Intake for calcium (P = 0.01) and vitamin D (P = 0.02) from supplement use. Fat intake predicted ghrelin, insulin, and IGF-I concentrations; carbohydrate intake predicted adiponectin. Resting energy expenditure was lower (P < 0.0001) and leisure activity levels higher in the AN group. CONCLUSIONS: Despite outpatient follow-up, community-dwelling girls with AN continue to have lower fat and higher fiber intakes than do healthy adolescents, which results in lower calorie intakes. Nutritionally related hormones are associated with specific nutrient intakes.     

A truncated polycystin-2 protein causes polycystic kidney disease and retinal degeneration in transgenic rats

The cloning of the PKD1 and PKD2 genes has led to promising new insight into the mechanisms that are responsible for cyst development in patients with autosomal dominant polycystic kidney disease. Although the dominant pattern of inheritance would argue for haploinsufficiency, a gain of function, or a dominant negative mechanism, there is good evidence that autosomal dominant polycystic kidney disease behaves like a recessive disease on a cellular level (two-hit mechanism of cystogenesis). For testing of whether other pathomechanisms in addition to the two-hit hypothesis can explain cyst formation, two transgenic rat lines that contain a truncated human polycystin-2 cDNA were generated. The protein product lacks almost the entire COOH-terminus and mimics mutations that frequently are found in patients. The transgene-encoded mRNA could be detected in multiple tissues of both transgenic lines, with the highest expression in the kidney. Both lines present with renal cysts that originate predominantly from the proximal tubule; in the tubular epithelial cells, the epitope-tagged mutant protein was detected in the brush border and in primary cilia. Further evidence of the involvement of primary cilia stems from the finding of retinal degeneration in the transgenic rats and from the fact that stably transfected LLC-PK(1) cells that inducibly produced the truncated polycystin-2 protein elaborated shorter cilia. Other experimental approaches, such as a knock-in strategy, will be necessary to validate these results, but this is the first preliminary evidence that cyst formation is due not only to somatic mutations.     

Clinical impact of chronic renal insufficiency on endovascular aneurysm repair

Endovascular aneurysm repair of abdominal aortic aneurysms has become a viable alternative to open repair. A significant proportion of this patient population has chronic renal insufficiency. The surgical outcomes associated with endovascular repair in 342 patients, with and without chronic renal insufficiency, are reported. Perioperative mortality, length of admission, length of intensive care unit admission, and rates of acute renal failure, congestive heart failure, myocardial infarction, conversion to open surgery, progression to hemodialysis, and incidence of endoleaks were retrospectively reviewed and analyzed. Endovascular repair demonstrated higher rates of acute renal failure, longer length of stay, and longer intensive care unit admissions in patients with chronic renal insufficiency. Patients with severe renal dysfunction demonstrated markedly elevated mortality and morbidity. These results indicate that chronic renal insufficiency is not an absolute contraindication to endovascular repair in patients with moderate renal dysfunction, but patients with severe renal dysfunction perform poorly after aortic reconstruction.