Isocitratase studies in Neurospora

Isocitratase studies in Neurospor

Warthin-Tumor mit Karzinom: Maligne Transformation oder Metastase?

Zusammenfassung: Wir berichten über einen ungewöhnlichen Fall eines langjährig klinisch diagnostizierten Warthin-Tumors (WT) mit plötzlicher Größenzunahme und nachfolgender Resektion. Histologisch konnte der WT bestätigt werden, zeigte jedoch zusätzlich diffuse Infiltrate eines dissolut wachsenden Adenokarzinoms. Unter der Annahme eines maligne transformierten WT wurden radiologische Staging-Untersuchungen angeschlossen, mit deren Hilfe ein metastasierendes Mammakarzinom mit identischer Morphologie zu den WT-Infiltraten entdeckt wurde. Die seltene Diagnose eines maligne transformierten WT erfordert daher immer den Ausschluss eines metastasierten Tumorleiden

Regulation of the MEX-5 Gradient by a Spatially Segregated Kinase/Phosphatase Cycle

SummaryProtein concentration gradients encode spatial information across cells and tissues and often depend on spatially localized protein synthesis. Here, we report that a different mechanism underlies the MEX-5 gradient. MEX-5 is an RNA-binding protein that becomes distributed in a cytoplasmic gradient along the anterior-to-posterior axis of the one-cell C. elegans embryo. We demonstrate that the MEX-5 gradient is a direct consequence of an underlying gradient in MEX-5 diffusivity. The MEX-5 diffusion gradient arises when the PAR-1 kinase stimulates the release of MEX-5 from slow-diffusive, RNA-containing complexes in the posterior cytoplasm. PAR-1 directly phosphorylates MEX-5 and is antagonized by the spatially uniform phosphatase PP2A. Mathematical modeling and in vivo observations demonstrate that spatially segregated phosphorylation and dephosphorylation reactions are sufficient to generate stable protein concentration gradients in the cytoplasm. The principles demonstrated here apply to any spatially segregated modification cycle that affects protein diffusion and do not require protein synthesis or degradation

Peripheral CA 125 levels in patients with uterine fibroids

CA 125, a marker of ovarian cancer, is also increased in otherwise normal women suffering from, for example, pelvic inflammatory disease, endometriosis and adenomyosis. The tissues suspected of producing CA 125 in normal women include the endometrium, the ovary and the peritoneum. This study was based on the hypothesis that uterine myomata would distend the peritoneum covering the uterus and thereby increase the peripheral levels of CA 125. To verify this hypothesis we measured CA 125 by an immunoradiometric assay in eight normal women every second day throughout the cycle and in 26 women with uterine fibroids before and after hysterectomy and at 8 and 12 weeks during gonadotrophin releasing hormone (GnRH) analogue therapy. In normal women no difference was observed between CA 125 levels in the follicular phase or in the luteal phase of the cycle. Over one-third (10/26) of the patients with uterine fibroids had increased (<90th centile of the controls) levels of CA 125 before GnRH therapy or hysterectomy. Removal of the uterus or administration of GnRH significantly decreased peripheral concentrations of CA 125 to levels below those observed in normal women. Furthermore, a significant positive correlation was observed between the levels of CA 125 and the volume of myomata as assessed by ultrasound. We conclude that in those cases of uterine fibroids where CA 125 is increased, monitoring this parameter during GnRH therapy is a good indirect measurement of regression of myomat

A role for suppressed thermogenesis favoring catch-up fat in the pathophysiology of catch-up growth

Catch-up growth is a risk factor for later obesity, type 2 diabetes, and cardiovascular diseases. We show here that after growth arrest by semistarvation, rats refed the same amount of a low-fat diet as controls show 1) lower energy expenditure due to diminished thermogenesis that favors accelerated fat deposition or catch-up fat and 2) normal glucose tolerance but higher plasma insulin after a glucose load at a time point when their body fat and plasma free fatty acids (FFAs) have not exceeded those of controls. Isocaloric refeeding on a high-fat diet resulted in even lower energy expenditure and thermogenesis and increased fat deposition and led to even higher plasma insulin and elevated plasma glucose after a glucose load. Stepwise regression analysis showed that plasma insulin and insulin-to-glucose ratio after the glucose load are predicted by variations in efficiency of energy use (i.e., in thermogenesis) rather than by the absolute amount of body fat or plasma FFAs. These studies suggest that suppression of thermogenesis per se may have a primary role in the development of hyperinsulinemia and insulin resistance during catch-up growth and underscore a role for suppressed thermogenesis directed specifically at catch-up fat in the link between catch-up growth and chronic metabolic diseases

Leptin directly stimulates thermogenesis in skeletal muscle

AbstractUsing a method involving repeated oxygen uptake (MO2) determinations in skeletal muscle ex vivo, the addition of leptin was found to increase MO2 in soleus muscles from lean mice. These effects were found to be inhibited by phosphatidylinositol 3-kinase inhibitors, absent in muscles from obese Leprdb mice which have the dysfunctional long form of leptin receptor, and blunted in muscles from diet-induced obese mice in the fed state but not during fasting. These findings indicate that leptin has direct thermogenic effects in skeletal muscle, and that these effects require both the long form of leptin receptors and phosphatidylinositol 3-kinase signalling

Carboxy-Terminal Truncation Activates glp-1 Protein to Specify Vulval Fates in Caenorhabditis elegans

The glp-1 and lin-12 genes encode homologous transmembrane proteins that may act as receptors for cell interactions during development. The glp-1 product is required for induction of germ-line proliferation and for embryogenesis. By contrast, lin-12 mediates somatic cell interactions, including those between the precursor cells that form the vulval hypodermis (VPCs). Here we analyse an unusual allele of glp-1, glp-1(q35), which displays a semidominant multivulva phenotype (Muv), as well as the typical recessive, loss-of-function Glp phenotypes (sterility and embryonic lethality). We find that the effects of glp-1(q35) on VPC development mimic those of dominant lin-12 mutations, even in the absence of lin-12 activity. The glp-1(q35) gene bears a nonsense mutation predicted to eliminate the 122 C-terminal amino acids, including a ProGluSerThr (PEST) sequence thought to destabilize proteins. We suggest that the carboxy terminus bears a negative regulatory domain which normally inactivates glp-1 in the VPCs. We propose that inappropriate glp-1(q35) activity can substitute for lin-12 to determine vulval fate, perhaps by driving the VPCs to proliferate

Hemolysis following coil embolization of a patent ductus arteriosus

We describe the development of hemolysis from moderate residual shunting across a patent ductus arteriosus following coil embolization. The fall in hemoglobin levels from 11.6 to 6.0 gm/dl necessitated a second coil procedure which resulted in complete closure of the residual shunting and resolution of hemolysis. Therefore, appearance of anemia following coil embolization of patent ductus arteriosus should be monitored closely; however, repeat coil embolization with elimination of residual shunt will lead to prompt recovery of normal hemoglobin levels. © 1996 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38225/1/17_ftp.pd