Induction of replicative competence ("priming") in normal liver

We have used a system of nutritional manipulation to investigate whether hepatocytes of the normal liver can be primed for replication in vivo. In this system, rats that are denied protein for 3 days undergo a burst of hepatic DNA synthesis and mitosis when they are refed amino acids, while normally fed or starved rats do not respond. To determine if hepatocytes of protein deprived (PD) rats have been "primed" for replication, we examined changes in protooncogene expression in livers of PD rats to see if they would mimic the pattern of gene expression that is induced early after partial hepatectomy. c-jun, c-myc, and p53 mRNAs were elevated in livers of PD rats, while c-fos and c-ras genes were not expressed. The administration of amino acids to PD rats stimulated hepatic DNA synthesis in a shorter period than is required after partial hepatectomy and induced p53 and c-ras expression. In culture, hepatocytes from PD rats had higher levels of c-myc mRNA, underwent morphological changes more rapidly, and reached maximum rates of DNA synthesis earlier than normal hepatocytes. In both normal and primed hepatocyte cultures, transforming growth factor alpha stimulated DNA synthesis more effectively than epidermal growth factor. We conclude that hepatocytes pass through a priming stage before they proliferate and that replicative competence without DNA synthesis can be induced in hepatocytes in the normal liver.     

Expression of hepatocyte and oval cell antigens in hepatocellular carcinomas produced by oncogene-transfected liver epithelial cells

We have established an in vivo/in vitro system in which epithelial cells ("oval cells") isolated from livers of rats fed a carcinogenic diet for a very brief period are placed in culture and transfected with an oncogene. Injection s.c. into nude mice of oval cells transfected with the activated c-Ha-ras (EJ oncogene) produces tumors with morphological features of differentiated hepatocellular carcinomas. Using monoclonal antibodies that can recognize hepatocyte, oval cell, and tumor antigens, we investigated the expression of these antigens in oval cells in culture, transfected with either the EJ oncogene or the normal c-Ha-ras allele and in tumors derived from the oncogene-transfected cells. We show that EJ-transfected cells and most particularly the tumors they produce expressed hepatocyte and oval cell antigens not detectable in untransfected cells or cells transfected with the normal c-Ha-ras gene. Furthermore, we found that in cloned tumor cells, the expression of hepatocyte antigens could be induced by changes in culture conditions and was accompanied by a decrease in the expression of oval cell markers. Trabecular hepatocellular carcinomas had higher reactivity toward monoclonal antibodies recognizing hepatocyte antigens while tumors with glandular architecture reacted predominantly with monoclonal antibodies against oval cells. We conclude that, in addition to its tumorigenic effect, the EJ oncogene induced the differentiation of tumor cells toward the hepatocyte lineage. In addition, the data provide further confirmation that oval cells can serve as progenitors of differentiated hepatocellular carcinomas.     

Effects of ankle sprain in a general clinic population 6 to 18 months after medical evaluation

OBJECTIVE: To assess the 1-year outcome of standard medical care of acute ankle sprains in a general clinic-based population. DESIGN: A self-administered survey was mailed to all adult patients who presented to a health system provider for evaluation of ankle sprain. SETTING: A regional primary care health system. PARTICIPANTS: Four hundred sixty-seven (66.5%) of 702 patients with ankle sprains evaluated by a system physician from April 1, 1995, to March 31, 1996. MAIN OUTCOME MEASURES: Prevalence and severity of self-reported ankle pain, swelling, perceived instability, and perceived weakness 6 to 18 months after medical evaluation. RESULTS: Most patients sought medical evaluation shortly after injury and were immobilized or braced; 32.7% reported formal or home-based physical therapy. Six to 18 months after injury, 72.6% reported residual symptoms. Of these, 40.4% reported at least 1 moderate to severe symptom, most commonly perceived ankle weakness; 40.3% were unable to walk 1 mile; and 43.3% were unable to jump or pivot on the ankle without symptoms. Factors associated with moderate to severe residual symptoms were reinjury of the ankle (odds ratio [OR], 7.21; 95% confidence interval [CI], 4.14-12.68), activity restriction longer than 1 week (OR, 2.04; 95% CI, 1.25-3.32), and limited weight bearing longer than 28 days (OR, 2.16; 95% CI, 1.28-3.63). CONCLUSIONS: Residual lifestyle-limiting symptoms are common 6 to 18 months after an ankle sprain. Ankle sprains may be more problematic than generally thought, or standard medical treatment may be inadequate. Further studies evaluating treatment regimens are needed to identify effective methods to reduce the long-term functional limitations of ankle sprain in general clinic populations.     

Lactose-derived oligosaccharides in the milk of elephants: comparison with human milk

Human milk is commonly considered to be unique when compared with the milk of other species with regard to its high content of complex fucosylated and sialylated lactose-derived oligosaccharides. We describe the application of high-pH anion-exchange chromatography with pulsed amperometric detection and TLC to characterize and quantitate neutral and sialylated lactose-derived oligosaccharides in milk from three Asian elephants and human milk. The lactose contents of elephant and human milks were 25-30 g/l and about 66 g/l respectively, whereas total oligosaccharide concentration was about three times higher in elephant milk and comprised up to 40% (10% in human milk) of the carbohydrate content. The ratio neutral: acidic components was different in the milk of the two species; in elephant milk, the N-acetylneuraminic acid-containing oligosaccharides made up almost half of the total amount v. 30% in human milk. Most oligosaccharides in elephant milk were more fucosylated and/or sialylated compared with human milk components. By mild acid hydrolysis, fucose and N-acetylneuraminic acid were cleaved off from complex components, and this resulted in increased amounts of fucose, galactose, N-acetylneuraminic acid, lactose and lacto-N-neo-tetraose. Unique to elephant milk are the high levels of 3'-galactosyllactose (up to 4 g/l) and lacto-N-neo-tetraose which are present in human milk only in trace amounts. Elephant and human milks have high levels and unique patterns of oligosaccharides which may reflect the relative importance of these components in neonatal host defence, in endothelial leucocyte interactions or in brain development.     

A reexamination of various extraoral appliances in light of recent research findings

The location of the center of resistance of the dentomaxillary complex has recently been identified more accurately than before. Based on this new finding, various modifications of the common facebow are presented for use in protraction therapy. Clinical applications for specific treatment objectives are also reviewed. Orthopedic and biomechanical implications of various standard retraction type extraoral appliances are also analyzed.     

Particle-mediated DNA immunization of cattle confers long-lasting immunity against bovine herpesvirus-1

Particle-mediated delivery was used as a method to vaccinate ruminants with a DNA vaccine. The optimal conditions for gene gun-based delivery of gold particles into the epidermal layer of the skin were determined. After delivery of the gold particles, an inflammatory response was observed. This response occurred regardless of the presence of plasmid and therefore was a result of the physical disturbance of the skin by the gold particles. To identify transfected cells, a plasmid expressing a green fluorescent protein was delivered into the skin. Fluorescent cells were located primarily in the outermost layers of the epidermis and outside the core of gold particles deposited by the gene gun. Cattle were immunized by gene gun with a plasmid expressing a truncated, secreted form of bovine herpesvirus-1 glycoprotein D. Serum antibody responses, antigen-specific proliferation, and interferon-gamma secretion by peripheral blood lymphocytes were demonstrated. These immune responses were found to be of long duration and sufficient magnitude to protect cattle against challenge with bovine herpesvirus-1, which demonstrates the efficacy of gene gun-based delivery of DNA vaccines to target species.     

Treatment of shoulder deformity in acquired spasticity

Cerebrovascular accidents and traumatic brain injury produce most of the deformities seen in patients with spastic imbalance of the shoulder. A general awareness of the global neurologic defect is required to understand appropriate treatment alternatives. Conservative treatment techniques include early initiation of therapy exercises. Muscle or nerve block treatments may prevent severe shoulder contractures. Diagnostic blocks may help differentiate between deformity caused by spasticity and that caused by fixed soft tissue contracture. Operative release procedures are described. These operations, when combined with appropriate postoperative therapy programs, permit correction of contractures caused by unbalanced muscle forces around the shoulder in patients with severe spasticity who do not respond to conservative care.     

Measuring developmental and functional status in children with disabilities

This study compared performance on the Functional Independence Measure for Children (WeeFIM), the Battelle Developmental Inventory Screening Test (BDIST), and the Vineland Adaptive Behavior Scales (VABS) in children with developmental disabilities. The three instruments were administered to 205 children with identified disabilities. All 205 children were tested using the WeeFIM instrument. The BDIST was administered to 101 children and the VABS to the remaining 104 children. Administration was counterbalanced and randomized across all three instruments. A proportional sampling plan was used to select the 205 children, who ranged in age from 11 to 87 months. A variety of medical diagnoses and levels of severity of motor, cognitive, and communication impairments were systematically included in the sample. Correlations (r) among subscales for all three instruments ranged from 0.42 to 0.92. Correlations for total scores ranged from 0.72 to 0.94. Analyses of potential moderator variables found no significant relation between age and severity of disability (r=0.05) or between socioeconomic status (SES) and severity of disability (r=0.21). Correlations with age were strongest for those subscale scores involving gross and fine motor skills. Correlations with SES and subscale scores ranged from 0.03 to 0.18. The three instruments provide important information regarding childhood performance in motor, self-care, communicative, cognitive, and social skills. The WeeFIM instrument requires less administration time and provides information directly relevant to evaluating functional outcomes for children with disabilities and their families.