Quantitative comparison of the microscopic anatomy of the human ACL femoral and tibial entheses

The femoral enthesis of the human anterior cruciate ligament (ACL) is known to be more susceptible to injury than the tibial enthesis. To determine whether anatomic differences might help explain this difference, we quantified the microscopic appearance of both entheses in 15 unembalmed knee specimens using light microscopy, toluidine blue stain and image analysis. The amount of calcified fibrocartilage and uncalcified fibrocartilage, and the ligament entheseal attachment angle were then compared between the femoral and tibial entheses via linear mixed‐effects models. The results showed marked differences in anatomy between the two entheses. The femoral enthesis exhibited a 3.9‐fold more acute ligament attachment angle than the tibial enthesis (p < 0.001), a 43% greater calcified fibrocartilage tissue area (p < 0.001), and a 226% greater uncalcified fibrocartilage depth (p < 0.001), with the latter differences being particularly pronounced in the central region. We conclude that the ACL femoral enthesis has more fibrocartilage and a more acute ligament attachment angle than the tibial enthesis, which provides insight into why it is more vulnerable to failure. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1811–1817, 2015.     

Localisation of vitronectin receptor immunoreactivity and tartrate resistant acid phosphatase activity in synovium from patients with inflammatory or degenerative arthritis.

The influx of cells into the synovial intima in rheumatoid joints may include osteoclasts and their precursors. The distribution of osteoclast markers--namely, tartrate resistant acid phosphatase activity and the expression of vitronectin receptor (shown with monoclonal antibodies 13C2 and 23C6)--was therefore examined in synovium obtained from patients with rheumatoid (RA) or degenerative (OA) arthritis. Tartrate resistant acid phosphatase positive cells were found in frozen sections of 60% (n = 30) of RA and 69% (n = 29) of OA synovial membranes. Whereas all synovia tested (four RA, four OA) showed diffuse staining of the lining cells with 13C2, 55% (n = 11) of RA and 57% (n = 14) of OA synovial membranes contained isolated cells stained with 23C6 scattered throughout the tissue. In cultures of synovial cells, tartrate resistant acid phosphatase positive, multinuclear, and 23C6 positive cells were found; these cells did not, however, form resorption pits on bone slices. The results show that fully differentiated osteoclasts are uncommon in synovium from patients with either degenerative or inflammatory arthropathies.     

Molecular characterization of human factor XSan Antonio

Enzymatic amplification technique was used to isolate all eight exons and sequences around the splice junctions, putative promoter, and polyadenylation sites of human factor X DNA from a patient with factor X deficiency. Two genetic changes in factor X have been observed in this patient. The patient is most likely a compound heterozygote since there is only 14% activity associated with factor X. A point mutation that resulted in the substitution of cysteine (TGC) for arginine (CGC) at amino acid 366 was found in exon VIII of one allele of the factor X gene. This mutation, which occurs in the catalytic domain, can affect the formation of a disulfide bridge and thus could result in a reduction in factor X activity. Sequencing all the regions revealed a second mutation: a deletion of one nucleotide (TCCT to TCT) in exon VII that would cause a frame shift at amino acid 272 followed by termination. We have also shown that the point mutation in exon VIII creates an ApaL1 restriction site and destroys the HinP1 site. Enzymatic DNA amplification followed by restriction digestion provides a quick, reliable, and sensitive method for carrier detection and antenatal diagnosis in affected kindreds. This is the first characterization of factor X deficiency at the molecular level. We propose to name this mutation Factor XSan Antonio.     

Activation of the coagulation cascade after infusion of a factor XI concentrate in congenitally deficient patients

Virally inactivated, high-purity factor XI concentrates are available for treatment of patients with factor XI deficiency. However, preliminary experience indicates that some preparations may be thrombogenic. We evaluated whether a highly purified concentrate produced signs of activation of the coagulation cascade in two patients with severe factor XI deficiency infused before and after surgery. Signs of heightened enzymatic activity of the common pathway of coagulation (elevated plasma levels of prothrombin fragment 1 + 2 and fibrinopeptide A) developed in the early post-infusion period, accompanied by more delayed signs of fibrin formation with secondary hyperfibrinolysis (elevated D-dimer and plasmin-antiplasmin complex). These changes occurred in both patients, but were more severe in the older patient with breast cancer when she underwent surgery, being accompanied by fibrinogen and platelet consumption. There were no concomitant signs of heightened activity of the factor VII-tissue factor mechanism on the factor Xase complex (plasma levels of activated factor VII and of factor IX and X activation peptides did not increase). The observed changes in biochemical markers of coagulation activation indicate that concentrate infusions increased thrombin generation and activity and that such changes were magnified by malignancy and surgery. Because some factor XI concentrates may be thrombogenic, they should be used with caution, especially in patients with other risk factors for thrombosis.     

Purification, molecular cloning, and sequence analysis of sucrose-6F-phosphate phosphohydrolase from plants

Sucrose-6(F)-phosphate phosphohydrolase (SPP; EC ) catalyzes the final step in the pathway of sucrose biosynthesis and is the only enzyme of photosynthetic carbon assimilation for which the gene has not been identified. The enzyme was purified to homogeneity from rice (Oryza sativa L.) leaves and partially sequenced. The rice leaf enzyme is a dimer with a native molecular mass of 100 kDa and a subunit molecular mass of 50 kDa. The enzyme is highly specific for sucrose 6(F)-phosphate with a K(m) of 65 microM and a specific activity of 1250 micromol min(-1) mg(-1) protein. The activity is dependent on Mg(2+) with a remarkably low K(a) of 8-9 microM and is weakly inhibited by sucrose. Three peptides from cleavage of the purified rice SPP with endoproteinase Lys-C showed similarity to the deduced amino acid sequences of three predicted open reading frames (ORF) in the Arabidopsis thaliana genome and one in the genome of the cyanobacterium Synechocystis sp. PCC6803, as well as cDNA clones from Arabidopsis, maize, and other species in the GenBank database of expressed sequence tags. The putative maize SPP cDNA clone contained an ORF encoding a 420-amino acid polypeptide. Heterologous expression in Escherichia coli showed that this cDNA clone encoded a functional SPP enzyme. The 260-amino acid N-terminal catalytic domain of the maize SPP is homologous to the C-terminal region of sucrose-phosphate synthase. A PSI-BLAST search of the GenBank database indicated that the maize SPP is a member of the haloacid dehalogenase hydrolase/phosphatase superfamily.     

Enantiospecific Reassessment of the Pharmacokinetics and Pharmacodynamics of Oral Eflornithine against Late-Stage Trypanosoma brucei gambiense Sleeping Sickness

This study aimed to characterize the stereoselective pharmacokinetics of oral eflornithine in 25 patients with late-stage Trypanosoma brucei gambiense sleeping sickness. A secondary aim was to determine the concentrations of l- and d-eflornithine required in plasma or cerebrospinal fluid (CSF) for an efficient eradication of the T. brucei gambiense parasites. Patients were randomly allocated to receive either 100 (group I, n = 12) or 125 (group II, n = 13) mg/kg of body weight of drug every 6 h for 14 days. The concentrations of l- and d-eflornithine in the plasma and CSF samples were measured using a stereospecific liquid chromatographic method. Nonlinear mixed-effects modeling was used to characterize the plasma pharmacokinetics. The plasma concentrations of l-eflornithine were on average 52% (95% confidence interval [CI], 51, 54%; n = 321) of the d-enantiomer concentrations. The typical oral clearances of l- and d-eflornithine were 17.4 (95% CI, 15.5, 19.3) and 8.23 (95% CI, 7.36, 9.10) liters/h, respectively. These differences were likely due to stereoselective intestinal absorption. The distributions of eflornithine enantiomers to the CSF were not stereoselective. A correlation was found between the probability of cure and plasma drug exposure, although it was not more pronounced for the l-enantiomer than for that of total eflornithine. This study may explain why oral treatment for late-stage human African trypanosomiasis (HAT) patients with racemic eflornithine has previously failed; the more potent l-enantiomer is present at much lower concentrations in both plasma and CSF than those of the d-enantiomer. Eflornithine stereoselective pharmacokinetics needs to be considered if an oral dosage regimen is to be explored further.     

Incidence and Survival Patterns of Sinonasal Undifferentiated Carcinoma in the United States

Objective To determine trends in sinonasal undifferentiated carcinoma (SNUC) survival patterns in the United States. Design Retrospective review of national database. Participants All cases of SNUC in the National Cancer Institute''s Surveillance Epidemiology and End Results program from 1973 to 2010 were examined. Main Outcome Measures Age-adjusted incidence and survival rates were calculated and stratified by demographic information and treatment modality. Cohort analysis was performed to analyze survival patterns over time. Results A total of 318 SNUC cases were identified. Age-adjusted incidence rate (IR) was 0.02 per 100,000. Incidence was greater in males (IR: 0.03) than females (IR: 0.01; p = 0.03). Overall 5- and 10-year relative survival rate was 34.9% and 31.3%, respectively. Overall median survival was 22.1 months. Median survival following surgery combined with radiation was 41.9 months. Five-year relative survival rate following surgery, radiation, or surgery combined with radiation was 38.7%, 36.0%, and 39.1%, respectively. Median survival from 1973–1986 and 1987–2010 was 14.5 and 23.5 months, respectively. Conclusions This study provides new data regarding survival patterns of SNUC in the United States, confirming survival benefit with surgery and radiation as well as identifying a trend toward improved survival in recent decades.     

Antibody responses to nasopharyngeal carriage of Streptococcus pneumoniae in adults: a longitudinal household study

BACKGROUND: Natural immunity to Streptococcus pneumoniae is thought to be induced by exposure to S. pneumoniae or cross-reactive antigens. No longitudinal studies of carriage of and immune responses to S. pneumoniae have been conducted using sophisticated immunological laboratory techniques. METHODS: We enrolled 121 families with young children into this study. Nasopharyngeal (NP) swabs were collected monthly for 10 months from all family members and were cultured in a standard fashion. Cultured S. pneumoniae isolates were serotyped. At the beginning (month 0) and end (month 10) of the study, venous blood was collected from family members >18 years old. Serotype-specific antipolysaccharide immunoglobulin G (IgG) and functional antibody and antibodies to pneumolysin, pneumococcal surface protein A (PspA), and pneumococcal surface antigen A (PsaA) were measured in paired serum samples. RESULTS: Levels of anticapsular IgG increased significantly after carriage of serotypes 9V, 14, 18C, 19F, and 23F by an individual or family member. For serotype 14, a higher level of anticapsular IgG at the beginning of the study was associated with reduced odds of carriage (P = .006). There was a small (approximately 20%) but significant increase in titers of antibodies to PsaA and pneumolysin but no change in titers of antibody to PspA. CONCLUSIONS: Adults respond to NP carriage by mounting anticapsular and weak antiprotein antibody responses, and naturally induced anticapsular IgG can prevent carriage.