The effects of aspartame on mast cells and basophils

The artificial sweetener aspartame was studied to determine whether it had any direct effects on mast cells and basophils. Aspartame was not shown to be a direct mast cell or basophil secretagogue in vitro, or in vivo as assessed by skin testing. During an acute incubation, aspartame did not affect IgE-mediated histamine release from mast cells. However, mast cells cultured in aspartame for periods of up to 9 days showed enhanced rates of proliferation and decreased responsiveness to releasing stimuli. The effect of aspartame on proliferation of cells in culture could be ascribed to a non-specific enhancing effect of its constituent amino acids.     

Lead retention in blood and brain after preweaning low-level lead exposure in the rat

Newborn rats of the albino Wistar strain were exposed to lead from birth to 20 days of age through mothers milk, from dams which were fed diets containing 0, 0.25, 0.5 or 1.0% powdered lead. Subsequent determination of tissue lead revealed a direct relationship between the lead levels in both blood and brain of the pups and the lead dosage to which they were indirectly exposed via the dams' milk. Lead retention in both tissues was still evident at 100 days of age, with the relative elevation of lead levels being an order of magnitude higher in brain than in blood. There were no obvious signs of lead intoxication in the pups, apart from mild growth retardation in the group with the highest lead burden. However there was a significant retardation in behavioral development observed on two of four measures which were employed. It was concluded that brief exposure to low lead levels in infancy can have long lasting consequences in the brain and in behavior.     

Effects of pca and dmae on the nematode caenorhabditis briggsae

Concentration of 6.8 mM DMAE did not retard age pigment accumulation in Caenorhabditis briggsae. However, when the nematodes were exposed to 6.8 mM PCA + 68 mM DMAE combined, the accumulation of age pigment was significantly retarded. A combination of 3.4 mM DMAE + 3.4 mM PCA had no effect on age pigment. It is concluded from this study that PCA and DMAE act in concert to produce the observed effect on age pigment. In respect to this parameter neither molecule was effective alone. The results indicate that the effect of centrophenoxine on age pigment might be enhanced by retarding the hydrolysis of centrophenoxine. The accumulation of electron dense aggregates, thought to be aggregates of cross-linked molecules, was reduced by 6.8 PCA + 6.8 DMAE. It is suggested that centrophenoxine be tested for its ability to remove random, unwanted cross-linkages in higher animals.     

Long-term followup after laparoscopic radical nephrectomy

PURPOSE: Laparoscopic radical nephrectomy has been shown to be less morbid than traditional open radical nephrectomy. The long-term oncological effectiveness of laparoscopic radical nephrectomy remains to be established. MATERIALS AND METHODS: At 3 centers patients undergoing laparoscopic radical nephrectomy before November 1, 1996 with pathologically confirmed renal cell carcinoma were identified. A representative group of patients undergoing open radical nephrectomy for clinical T1, T2 lesions was also identified. Staging, operative details and postoperative course were reviewed. Followup consisted of review of clinical, laboratory and radiological records. Kaplan-Meier analysis was performed. RESULTS: The study included 64 patients treated with laparoscopic and 69 treated with open radical nephrectomy with respective average ages of 60.6 and 61.3 years at surgery. On preoperative imaging open lesions were larger (6.2 cm., range 2.5 to 15) than laparoscopic radical nephrectomy lesions (4.3 cm., range 2 to 10, p <0.001). Pathology reports revealed no difference in specimen weight (425 and 495 gm., p = 0.146) or average Fuhrman grade (1.88 and 1.78, p = 0.476) between laparoscopic and open radical nephrectomy, respectively. Median followup was 54 months (range 0 to 94) for laparoscopic and 69 months (range 8 to 114) for open radical nephrectomy. Kaplan-Meier analysis with log rank comparison revealed 5-year recurrence-free survival of 92% and 91% for laparoscopic and open radical nephrectomy, respectively (p = 0.583). At 5 years cancer specific survival was 98% and 92% (p = 0.124), and nonspecific survival was 81% and 89% (p = 0.260) for laparoscopic and open radical nephrectomy, respectively. CONCLUSIONS: Laparoscopic radical nephrectomy confers long-term oncological effectiveness equivalent to traditional open radical nephrectomy.     

Tophaceous gout of the spine mimicking epidural infection: case report and review of the literature

OBJECTIVE AND IMPORTANCE: Tophaceous gout uncommonly affects the axial skeleton. The clinical presentations of gout of the spine range from back pain to quadriplegia. Gout that presents as back pain and fever may be difficult to distinguish from spinal infection. We present a case of a patient with tophaceous gout of the lumbar spine who was initially diagnosed with and treated for an epidural infection. The clinical and diagnostic features of tophaceous gout of the spine are reviewed. CLINICAL PRESENTATION: A 70-year-old man presented with a 2-day history of fever and back pain. A physical examination revealed that he had flank tenderness and evidence of polyarthritis affecting the elbows, knees, and right first metatarsophalangeal joint. A magnetic resonance imaging scan of the patient's lumbar spine showed an extensive area of abnormal gadolinium enhancement of the paramedian posterior soft tissues from L3 to S1 with an area of focal enhancement extending into the right L4-L5 facet joint. INTERVENTION: A laminectomy was performed at L4-L5, and a chalky white material in the facet joint was found eroding into the adjacent pars intra-articularis. Light and polarizing microscopy confirmed the presence of gouty tophus. No evidence of infection was found. CONCLUSION: Gouty arthritis of the spine is rare. Thirty-seven previous cases have been reported. When the clinical presentation includes acute back pain and fever, differentiation of spinal gout from spinal infection may be difficult. The clinical suspicion of spinal gout may lead to the correct diagnosis by a less invasive approach than exploration and laminectomy.     

Fetal mouse skin heals scarlessly in a chick chorioallantoic membrane model system

In mammals, the early-gestation fetus has the regenerative ability to heal skin wounds without scar formation. This observation was first reported more than 3 decades ago, and has been confirmed in a number of in vivo animal models. Although an intensive research effort has focused on unraveling the mechanisms underlying scarless fetal wound repair, no suitable model of in vitro fetal skin healing has been developed. In this article, we report a novel model for the study of fetal wound healing. Fetal skin from gestational day 16.5 Balb/c mice (total gestation, 20 days) was grafted onto the chorioallantoic membrane of 12-day-old chicken embryos and cultured for up to 7 days. At 48 hours postengraftment, circular wounds (diameter = 1 mm) were made in the fetal skin using a rotating titanium sapphire laser (N = 45). The tissue was examined daily by visual inspection to look for signs of infection and ischemia. The grafts and the surrounding host tissue were examined histologically. In all fetal skin grafts, the wounds completely reepithelialized by postinjury day 7, with regeneration of the dermis. Fetal mouse skin xenografts transplanted onto the chorioallantoic membrane of fertilized chicken eggs provides a useful model for the study of fetal wound healing. This model can be used as an adjunct to traditional in vivo mammalian models of fetal repair.