Effects of pulsed electromagnetic fields on the mRNA expression of CAII and RANK in ovariectomized rats.

The present study was designed to determine the effects of pulsed electromagnetic fields (PEMFs) on the mRNA expression of the carbonic anhydrase II (CAII) and receptor activator of NF-κB (RANK) in ovariectomized rats. A total of 48 SD rats were randomly divided into four groups [Sham, OVX, PEMFs, and E(2) (premarin)], 12 rats in each group. Rats in the Sham group received sham ovariectomy, while rats in OVX, PEMFs, and E(2) groups received ovariectomy. Twelve weeks following the surgery, rats (whole body) in the PEMFs group were exposed to PEMFs for 30 days with 3.8 mT, 8 Hz, and 40 min per day; rats in the E(2) group were administered premarin (0.0625 mg/kg/d; intragastric administration 1-2 ml/100 g). Rats in the Sham and OVX groups housed in the same conditions. At the end of intervention, the level of serum estradiol of rats was measured. The gene expression of CAII and RANK in the left ilium of rats was determined with real-time fluorescent-nested quantitative polymerase chain reaction. Compared with the Sham group, the level of serum estradiol in the ovariectomized group was significantly decreased (P < 0.05); compared with the OVX group, CAIImRNA expression was significantly decreased in the PEMFs group and E group (P < 0.05, 0.01, respectively). Compared with the E group, RANKmRNA expression was significantly higher in the PEMFs group (P < 0.05); although RANKmRNA expression decreased in PEMFs group, no statistically significant difference was found between PEMF group and OVX group (P = 0.82). These data suggest that PEMFs could regulate the expression of CAIImRNA in ovariectomized rats.

Intraischemic hypothermia differentially modulates oxidative stress proteins during mesenteric ischemia/reperfusion.

BACKGROUND: Thoracoabdominal aortic aneurysm repair requires obligatory mesenteric ischemia/reperfusion (I/R), eliciting an inflammatory response resulting in gut dysfunction and remote organ injury. Therapeutic hypothermia has been advocated for organ protection (ie, brain, spinal cord, and kidneys) during extensive aortic operation, and it has also been shown to differentially modulate proinflammatory gene transcription in the central nervous system. In other I/R models, nuclear factor Kappa-B (NF-(kappa)B) and inducible nitric oxide synthase (iNOS) worsen while heme oxygenase-1 (HO-1) protects against injury. We examined the effects of regional intraischemic hypothermia on mesenteric I/R-induced mucosal injury, NF-kappaB activation, and expression of iNOS and HO-1. METHODS: Sprague-Dawley rats underwent sham laparotomy or superior mesenteric artery occlusion for 45 minutes with or without topical hypothermia (15 degrees -20 degrees C). Intestinal epithelial permeability to (14)C inulin was assessed at 6 hours of reperfusion. In a separate set of experiments, biopsies of the ileum were obtained at 6 hours of reperfusion for: 1) mucosal histologic injury assessed by a blinded observer; 2) NF-kappaB activation by electrophoretic mobility shift assay; and 3) iNOS and HO-1 protein expression by immunoblot. RESULTS: Mesenteric I/R significantly increased intestinal permeability to (14)C inulin, histologic injury, activation of NF-kappaB, and iNOS and HO-1 expression when compared with sham control rats. In contrast, rats treated with intraischemic topical hypothermia exhibited intestinal permeability comparable with sham control rats, and reduced histologic injury. In addition, hypothermia prevented the activation of NF-kappaB and iNOS expression, but had no effect on HO-1 expression. CONCLUSIONS: On the basis of these observations, we conclude that therapeutically applied intraischemic hypothermia protects the gut during mesenteric I/R. In addition, hypothermia prevented NF-kappaB activation while differentially modulating expression of the oxidative stress proteins iNOS and HO-1 in response to mesenteric I/R.

[The comparative biochemical and morphological characteristics of chondrosarcoma and giant-cell tumor of the bone]. / Sravnitel'naia biokhimicheskaia i morfologicheskaia kharakteristika khondrosarkomy i gigantokletochnoi opukholi kosti.

Spectrometry has been employed to assess the levels of collagenase, catepsin D, trypsin-like proteinases and their inhibitors as well as bone acid and alkaline phosphatase both in the center and along the periphery of giant cell tumor of bone (GCTB) and chondrosarcoma. The levels of collagenase, trypsin-like proteinases and their inhibitors in the center of chondrosarcoma were much higher while those of alkaline phosphatase--lower than along tumor periphery. The catepsin D and acid phosphatase concentrations of the center and periphery of chondrosarcoma were similar. It was suggested that an extremely low concentration of trypsin-like inhibitors may contribute to degradation of the matrix in tissues adjacent to chondrosarcoma and, consequently, to tumor invasion development.

The radiographic stage of giant cell tumor related to stromal cells' proliferation. Tissue cultures in 13 cases.

The clinical behavior of giant cell tumor is related to the radiological appearance. To test the hypothesis that in vitro proliferation of the neoplastic stromal cell population of giant cell tumors is related to the radiological appearance, this study was undertaken. A prospective analysis of the cells migrating from 13 consecutive tumors was conducted. Growth curves and population doubling-times (PDT) for first and fifth passages were calculated and alkaline phosphatase levels were measured and compared to preoperative radiographic staging. A strong negative correlation was found between PDT and the radiographic stage. Tumors in stages I and II (low aggressiveness) were found to have an average cell population doubling-time of 11 (SD 2.2) days, while those in stage III (high aggressiveness) showed a doubling-time of 6 (SD 2.2) days. Low alkaline phosphatase activity was noted in all cultures, a finding consistent with the putative preosteoblastic potential of these stromal cells. This putative origin is also indicated by the differentiation response to retinoic acid. The findings suggest that the in vitro proliferation of the mononuclear stromal cell population of giant cell tumors is related to the radiographic stage and may predict the clinical behavior of these tumors.

24,25-dihydroxy vitamin D3 treatment inhibits parathyroid-stimulated adenylate cyclase in iliac crest biopsies from uremic patients.

Renal osteodystrophy with increased bone resorption is a major clinical problem in patients with chronic renal failure. Previous reports have shown that treatment with 24,25-dihydroxy vitamin D3 (24,25(OH)2D3) may result in decreased bone resorption. The present study addresses basic mechanisms for the action of 24,25(OH)2D3 in bone of patients with elevated serum parathyroid hormone (PTH) levels due to chronic renal disease. Twenty-four patients 56 +/- 17 years old (mean +/- SE) with chronic kidney disease in the predialytic state (serum creatinine > 150 mumol/l) and elevated serum midregion PTH > 1.2 micrograms/l were randomly assigned to oral treatment with either 1,25-dihydroxy vitamin D3 (1,25(OH)2D3) (0.25-0.50 microgram/day), 24,25(OH)2D3 (daily dose of 15 micrograms), or a combination of the two vitamin D3 analogs. The control group received calcium carbonate (maximal dosage of 1 g x 3). Selected variables in serum and urine as well as hormone sensitive adenylate cyclase (AC) in iliac crest biopsies were assessed before treatment and during follow-up after two and six months. Serum levels of 1,25(OH)2D3 and 24,25(OH)2D3 were significantly (P < 0.05) increased after two and six months in the respective treatment groups. Net bone PTH-enhanced AC (PTH-AC) fell abruptly (P < 0.01) after two months of treatment and was nearly abolished (P < 0.01) after six months with 24,25(OH)2D3 given alone or in combination with 1,25(OH)2D3. An inverse relationship (r = -0.57, P < 0.05, n = 48) between net PTH-AC in bone and serum levels of 24,25(OH)2D3 was demonstrated. In all groups, serum total calcium (s-Ca) was maintained within normal range.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of parathyroid hormone (PTH) and 24,25-dihydroxy-vitamin D3 on adenylyl cyclase of iliac crest biopsies: diagnostic and prognostic tool for evaluation and treatment of uremic patients.

The bone adenylyl cyclase (AC) complex of iliac crest biopsies of normals, uremic patients and subjects with primary hyperparathyroidism (PrHPT) have been investigated. Bone resorption (RS) in uremic patients appears to be related partly to increased serum parathyroid hormone (s-PTH) levels and to netto PTH-stimulated AC (net PTH-AC) and partly to the uremic condition (as estimated by s-Creatinine) per se. Serum PTH is able to completely desensitize the PTH dependent bone AC in normals in vivo, but only partially in uremic patients. In patients with PrHPT, the bone AC appears to be inert to homologous desensitization. Positive aluminum staining is associated with blunted CT-responsive and low basal AC. In the combined group of normals and uremic patients, net PTH-AC is (as predicted from human in vitro data and the rat model) inversely related to serum 24,25-diOH-D3. Net PTH-AC, when corrected for s-24,25-diOH-D3 levels, correlated well with RS. The described action of 24,25-diOH-D3 presents a clearly defined rationale for the use of 24,25-diOH-D3 concurrently with 1,25-diOH-D3 to treat renal osteodystrophy: By administering 1,25-diOH-D3, s-Ca2+ and s-PTH will normalize and consequently net PTH-AC diminish. 24,25-diOH-D3 is then believed to further reduce net PTH-AC and RS. A concomitant alleviation of the uremic condition would eventually ensure the fastest possible restoration of bone structure and function.

[Microchemical investigation of alpha D-glucosidases using 4-methylumnelliferyl- and 2-naphthyl-alpha-d-glucoside (author's transl)]. / Mikrochemische Untersuchung der alpha-d-glucosidasen mit 4-Methylumbelliferyl- und 2-Naphthyl-alpha-d-glucosid.

In crude homogenates prepared from freeze-dried cryostate sections of various rat organs the Km and Vmax of acid and neutral alpha-glucosidase as well as the effect of the pH, substrate and enzyme concentration and the incubation time on the activity were determined fluorometrically with 4-methylumbelliferyl- and 2-naphthyl alpha-d-glucoside as substrates. On the basis of the biochemical data 2 assays were developed for the microchemical measurement of both alpha-glucosidases in groups of epithelial cells isolated from freeze dried cryostate sections of the epididymis, jejunum, ilium, liver and kidney of suckling and adult rats. The rate of hydrolysis of 2-naphthyl and 4-methylumbelliferyl alpha-d-glucoside differs moderately. However, due to the higher sensitivity of 4-methylumbelliferone the methylumbelliferyl derivative is preferable especially for the evaluation of alpha-d-glucosidases in cells with low enzyme activity.