Deconditioning reduces mineral content of the third metacarpal bone in horses

Diet and exercise are two management factors that affect bone density and strength. We proposed that bone density and calcium status would be affected by deconditioning for 12 wk and by dietary Ca concentration. Eleven highly conditioned Arabian horses were taken out of training and placed in stalls for 12 wk. Horses were walked on a mechanical walker in two 30-min sessions, 7 d/wk. Diets were designated CC (.36% Ca) and HC (.62% Ca). Data were collected every 21 d. Serum or plasma were analyzed for total and ionized Ca, parathyroid hormone, osteocalcin, hydroxyproline, electrolytes, and blood gases. Bone mineral content (BMC) of the left third metacarpal bone was estimated by radiographic photometry using an aluminum step wedge, which was exposed in each radiograph, as a reference standard for an image analysis system. During deconditioning, BMC decreased by approximately 1.1 g/2 cm, or .45% per week. This decrease was unaffected by dietary Ca. Serum Ca concentration increased with deconditioning. The results suggest that dietary Ca at twice the currently recommended level did not prevent the loss of BMC in response to deconditioning. Loss of BMC during 12 wk of stall confinement may weaken bones, increasing the risk of skeletal injuries when training is resumed.     

Ocular symptoms in association with antiphospholipid antibodies

OBJECTIVE: To describe the clinical and serologic findings of 50 antiphospholipid antibody (APA)-positive patients within a retrospective study. METHODS: Measurement of visual acuity, slit-lamp biomicroscopy, tonometry, fundus examination and perimetry. Laboratory tests were performed for detection of APA against thromboplastin and cardiolipin. Antinuclear antibodies (ANA), antibodies to dsDNA, antithyroidal and antiparietal antibodies were also tested. RESULTS: A combination of both transient and permanent visual disturbances was noticed in more than half of the patients. Transient visual disturbances included transient blurred vision, partial defects of the visual fields and amaurosis fugax. The most frequent permanent abnormalities were optic atrophy in 20 patients, due to AION in 9 cases, and disturbances of the choroidal circulation in 17 patients. Fourty-six patients had positive levels of thromboplastin APA; cardiolipin APA were found to be increased in 36 patients. CONCLUSIONS: We did not find a clear correlation between APA activity or the immunoglobulin classes in the individual and the severity of the ocular disease. The benefit from a therapy with the antiplatelet agent acetylsalicylic acid was evident in a reduction of the patients' transient visual disturbances and, in most cases, no further progression of permanent visual field defects was observed.     

Restoration of PEX2 peroxisome assembly defects by overexpression of PMP70

OBJECTIVES: To investigate articular cartilage collagen network, thickness of birefringent cartilage zones, and glycosaminoglycan concentration in macroscopically normal looking knee joint cartilage of young beagles subjected to experimental slowly progressive osteoarthritis (OA). METHODS: OA was induced by a tibial 30 degree valgus osteotomy in 15 female beagles at the age of 3 months. Fifteen sisters were controls. Cartilage specimens were collected seven (Group 1) and 18 months (Group 2) postoperatively. Collagen induced optical path difference and cartilage zone thickness measurements were determined from histological sections of articular cartilage with smooth and intact surface by computer assisted quantitative polarised light microscopy. Volume density of cartilage collagen fibrils was determined by image analysis from transmission electron micrographs and content of glycosaminoglycans by quantitative digital densitometry from histological sections. RESULTS: In the superficial zone of the lateral tibial and femoral cartilage, the collagen induced optical path difference (birefringence) decreased by 19 to 71% (p < 0.05) seven months postoperatively. This suggests that severe superficial collagen fibril network deterioration took place, as 18 months postoperatively, macroscopic and microscopic OA was present in many cartilage areas. Thickness of the uncalcified cartilage increased while the superficial zone became thinner in the same sites. In operated dogs, glycosaminoglycan content first increased (Group 1) in the lateral tibial condyle and then decreased (Group 2) (p < 0.05). CONCLUSION: In this OA model, derangement of the superficial zone collagen network was the probable reason for birefringence reduction. This change occurred well before macroscopic OA.     

Synthesis and two-dimensional electrophoretic analysis of mixed populations of circular and linear RNAs

Spontaneous cleavage of the less abundant form of tobacco ringspot virus satellite RNA is readily reversible. Capitalizing on earlier observations by Feldstein and Bruening that small 'mini-monomer' RNAs derived from this molecule and containing little more than covalently attached ribozyme and substrate cleavage products are able to efficiently circularize, we have constructed a series of self-circularizing RNAs of precisely known size. Mixtures of linear and circular RNAs synthesized in vitro and containing 225-1132 nt could be completely resolved using a novel two-dimensional denaturing polyacrylamide gel electrophoresis system. Similar analyses of a complex mixture of coconut cadang-cadang viroid RNAs revealed the presence of relatively large amounts of a previously undescribed 'fast-slow' heterodimeric RNA species in infected palms. Only a single DNA template is required to prepare each pair of circular and linear RNA markers.     

Escherichia coli and Lactobacillus plantarum responses to osmotic stress

Artificial insemination using cryopreserved semen is a common management tool of the contemporary livestock producer. However, cryopreservation is detrimental to sperm function and fertility, killing some 50% of the spermatozoa during the process. Prediction of cryopreservation damage from prefreeze samples remains elusive. Computer-automated sperm head morphometry was used in this study to determine the effects of cryopreservation on bovine sperm head morphometry. Semen was collected from 18 bulls and was divided. One portion was extended to 200 x 10(6) sperm/ml and a microscope slide was prepared, while the remaining portion was cryopreserved in a Triscitrate-yolk extender. After thawing, the cryopreserved samples were prepared on microscope slides. All slides were air dried and were stained with hematoxylin and rose bengal. The morphometric dimensions for length, width, width/length, area, and perimeter for a minimum of 200 sperm heads were analyzed from each slide by computer-aided sperm head morphometry analysis, and the mean measurements were recorded. Bull sperm heads were significantly (P < 0.01) smaller in cryopreserved spermatozoa than in the companion extended samples for length (8.56+/-0.07 vs. 8.63+/-0.08 microm), width (4.39+/-0.05 vs. 4.48+/-0.05 microm), area (28.42+/-0.07 vs. 29.14+/-0.08 microm), and perimeter (23.33+/-0.21 vs. 23.70+/-0.23 microm) for all bulls. Width/length was also different (0.513 vs. 0.519). In addition, differences (P < 0.05) were found within 14 of 18 bulls for at least four of the morphometric parameters. The percent change in measures after cryopreservation were correlated (P < or = 0.05) to the variability of the extended sample. Variations in sperm head measurements were lower (P < or = 0.05) in extended samples of the four bulls in which no changes occurred than in extended samples of the remaining 14 bulls. These data suggest that the variability in sperm head measurements of individual bulls, or ejaculates, may be an indicator of sperm cryosurvivability.     

Characterization of ovomucoid-specific T-cell lines and clones from egg-allergic subjects

Three-dimensional gel culture systems represent conditions that mimic the differentiated state of mesenchymal cells in vivo. We examined gel contraction, cell growth, and phenotypic modulation of rabbit arterial SMC in three-dimensional gel culture. The gel contraction rate was dependent on the collagen type; that is, the contraction by freshly isolated SMC was faster and more pronounced in type I collagen than in type III collagen. In contrast, the phenotypic modulation of SMC was independent of collagen type. The major portion of cells in both type I and III collagens with growth factors underwent transition from a contractile (G0 phase) to a synthetic phenotype (G1B phase), but this transition was clearly delayed compared with that on collagens. The cells had hardly begun DNA synthesis in either collagen type and failed to proliferate even after 10 days of culture. These results indicate that collagen type is important in gel contraction by vascular SMC, while the organization of collagen fibrils (two-dimensional vs three-dimensional) is more critical in the phenotypic transition and proliferation of these cells. However, the more specific organization of extracellular matrix than the collagen gel culture system may be necessary to maintain the contractile phenotype of SMC.     

Range of motion and complications after postburn heterotopic bone excision about the elbow

OBJECTIVE: To review the results of surgical management of heterotopic ossification about the elbow in burned patients. DESIGN: Retrospective analysis with long-term patient follow-up. MATERIALS AND METHODS: Eleven patients with 16 elbows requiring surgery were admitted between January 1, 1982 and December 31, 1993. A posterior approach to the elbow with release of the encased ulnar nerve +/- anterior transposition and transolecranon osteotomy to access extensive bone formation in the olecranon fossa was employed. Eight patients (11 elbows) were available for long-term follow-up conducted at mean 50 +/- 13 months after surgery. Long-term follow-up consisted of measurement of range of elbow motion, as well as clinical assessment of ulnar nerve function. MAIN RESULTS: For the 11 elbows examined postoperatively, the mean range of motion preoperatively in flexion-extension was 11 degrees +/- 5 degrees compared to 89 degrees +/- 12 degrees postoperatively (p < 0.001). Three patients with poor long-term results had ankylosis of the joint preoperatively. Of four patients with ulnar nerve paresis preoperatively, none had ulnar nerve dysfunction at follow-up. Of 16 elbows operated on, four (25%) had postoperative complications. Two suffered soft-tissue breakdown with hardware exposure requiring abdominal flap closure, one early failure of olecranon fixation, and one late infected hardware. CONCLUSIONS: Surgery for both limited range of motion as well as ulnar nerve compression is effective in cases of heterotopic ossification about the elbows of burned patients. Early operative intervention is indicated in progressive disease, particularly ulnar nerve palsy, if soft-tissue quality is adequate. Complications with 25% of elbows suggest that use of olecranon osteotomy for joint access may warrant review.     

Fluorouracil and leucovorin with or without interferon alfa-2b in advanced colorectal cancer: analysis of a prospective randomized phase III trial. Hellenic Cooperative Oncology Group

PURPOSE: To investigate if double modulation of fluorouracil (5-FU) with leucovorin (folinic acid [FA]) and interferon alfa-2b (IFN 2b) improves responses and survival in comparison to single modulation of 5-FU with FA. PATIENTS AND METHODS: One hundred six patients with histologically confirmed advanced colorectal cancer, measurable disease, and without previous chemotherapy were prospectively randomized into two groups. Patients in group A received 5-FU 450 mg/m2 as an intravenous bolus in the midinfusion of FA weekly. FA was given at a dose of 200 mg/m2 in 500 mL 0.9% normal saline solution in 2-hour infusion. Patients in group B received exactly the same regimen plus IFN 2b 5 million units subcutaneously three times weekly. RESULTS: All patients were well balanced in both groups regarding age, sex, performance status, number, and site of metastasis. One hundred two patients were assessable. All patients have died. There was no difference in response between the two groups (7.8% v 9.8%). Median survival was 10.1 months in group A, and 7.2 months in group B (P = .00189). Median time to progression was 8.4 and 5.2 months, respectively (P = .00196). Overall, better performance status and older age had a positive impact on survival. Toxicity was the most important and catastrophic aspect of this study. Patients who received IFN 2b had significantly worse anemia, neutropenia, diarrhea, anorexia, weight loss, flu-like syndrome, and psychological reactions. CONCLUSION: Based on this final analysis, the addition of IFN 2b to the combination of 5-FU and FA enhances toxicity and contributes to decreased survival.     

Influence of the angiotensin II antagonist valsartan on left ventricular hypertrophy in patients with essential hypertension

BACKGROUND: Left ventricular hypertrophy (LVH) represents an independent risk factor in patients with essential hypertension. Because reversal of LVH may be associated with an improvement of prognosis, the influence of new antihypertensive compounds, such as angiotensin II AT1 receptor antagonists, on LVH should be determined. METHODS AND RESULTS: In a randomized, double-blind trial, 69 predominantly previously untreated hypertensive patients with echocardiographically proven LVH, ie, left ventricular mass index (LVMI) >134 g/m2 in men and >110 g/m2 in women and/or end-diastolic septal thickness >12 mm, received either the angiotensin II antagonist valsartan or atenolol for 8 months. Echocardiographic data of 58 patients were available. After 8 months of valsartan treatment (n=29), LVMI decreased from 127+/-23 to 106+/-25 g/m2 (ratio [R]=0.83; 95% CI, 0.79 to 0.87; P<0.0001 versus baseline). Under atenolol (n=29), LVMI decreased to a smaller extent, from 127+/-25 to 117+/-27 g/m2 (R=0.92; 95% CI, 0.86 to 0.98; P=0.0082 versus baseline). The mean reduction of LVMI came to 21 g/m2 under valsartan and only to 10 g/m2 under atenolol (R=0.91; 90% CI, 0.85 to 0.97 versus atenolol). Baseline mean blood pressure values were determined to be 163+/-12/101+/-6 mm Hg before treatment with valsartan and 160+/-14/103+/-6 mm Hg before atenolol treatment. After 8 months of treatment, mean blood pressure decreased to 146+/-13/90+/-7 mm Hg with valsartan and to 147+/-18/90+/-7 mm Hg with atenolol. Nine patients in the valsartan group and 8 patients in the atenolol group required additional medication with hydrochlorothiazide. CONCLUSIONS: Antihypertensive treatment with the angiotensin II antagonist valsartan for 8 months produced a significant regression of LVH in predominantly previously untreated patients with essential hypertension. The drug may be safely administered in this subset of hypertensive patients; however, the long-term benefit in terms of risk reduction has still to be evaluated in further trials.