Chicken single-chain variable fragments against the SARS-CoV spike protein

The major concern for severe acute respiratory syndrome (SARS), caused by the SARS-associated coronavirus (SARS-CoV), is the lack of diagnostic and therapeutic agents. Using a phage display technology in a chicken system, high-affinity monoclonal antibody fragments against the SARS-CoV spike protein were characterized. Ten truncated spike protein gene fragments were expressed in Escherichia coli cells. Following the immunization of chickens with these recombinant spike proteins, two single-chain variable fragment (scFv) antibody libraries were established with short or long linkers to contain 5x10(7) and 9x10(6) transformants, respectively. After four rounds of panning selection, the scFv antibodies of randomly chosen clones were demonstrated by Coomassie blue staining, and verified by western blot analysis. In a comparison of nucleotide sequences with the chicken germline gene, we found that all clones varied in the complementarity-determining regions, that two scFv antibodies reacted significantly with SARS-CoV-infected Vero cells, and that those two specific scFv antibodies recognized the same region of the spike protein spanning amino acid residues 750-1000. In conclusion, the results suggest that the chicken scFv phage display system can be a potential model for mass production of high-affinity antibodies against the SARS-CoV spike protein.     

Ischemia/reperfusion-induced low reactivity of the rat superior mesenteric vascular bed is associated with expression of nitric oxide synthases

Our objective was to investigate the mRNA and protein expressions of eNOS and iNOS in the mesenteric vascular bed after ischemia and reperfusion of the rat superior mesenteric artery (SMA) and the role of nitric oxide (NO) in the response of the vascular bed to vasoconstrictors following reperfusion of the SMA. METHODS: Real-time polymerase chain reaction and immunohistochemistry were used to monitor the mRNA and protein expression of eNOS and iNOS after I/R challenge to the rat SMA. Ischemia was induced by clamping the SMA for 40 minutes, after which the flow was restored and the vessels were reperfused for 300 minutes. Blood samples were collected for assays of lactic dehydrogenase, tumor necrosis factor (TNF), hydroxyl radical, and NO. After ischemia/reperfusion, the vascular beds were separated for analysis of the expression of eNOS and iNOS. The SMA with its associated intestinal tissue was isolated and perfused in vitro with Tyrode's solution (N = 8) then challenged with phenylephrine. RESULTS: Reperfusion of the SMA induced an increase in blood concentrations of lactic dehydrogenase (P < .001; N = 8), hydroxyl radical (P < .05), TNF (P < .001), and NO (P < .05). ENOS and iNOS mRNA expression increased 1.3 +/- 0.1-fold and 19.6 +/- 3.5-fold, respectively when compared to the sham-operated group. Protein expression increased 1.9 +/- 0.4-fold and 12.6 +/- 3.1-fold, respectively, after reperfusion (N = 3) when compared with sham-treated rats. In vitro challenge showed that administration of phenylephrine (10(-8) approximately 10(-4) nmol) produced vasoconstriction in a dose-related manner. Maximum contractile responses to phenylephrine were attenuated in reperfused SMA. Addition of the NOS inhibitor N(G)-nitro-L-arginine (L-NNA, 10(-4) M) resulted in full recovery of the response to phenylephrine. CONCLUSIONS: Ischemia/reperfusion of the SMA results in a decrease in vascular reactivity of the mesenteric vessels that is dependent on NOS expression by the intestinal vascular bed.     

Choroidal neovascularisation secondary to Best’s disease in a 13-year-old boy treated by intravitreal bevacizumab

Background To describe the effect of intravitreal bevacizumab for the treatment of choroidal neovascularisation secondary to vitelliform dystrophy of the macula (Best’s disease). Methods A 13-year-old boy with confirmed Best’s disease presented with visual acuity (VA) loss due to secondary choroidal neovascularisation (CNV). He was treated with a single injection of 1-mg bevacizumab. Results Best corrected VA (Snellen) fully recovered from 20/40 preoperatively to 20/20 over a period of 6 months. Optical coherence tomography (OCT) and angiography demonstrated regression of the CNV and resolution of the macular edema. Conclusions A single intravitreal injection of bevacizumab may be effective to induce morphologic and functional improvement in a juvenile suffering from CNV secondary to Best’s disease. Proprietary interest: none for all authors     

Hypoglossal schwannoma in the submandibular space

Most schwannomas of the hypoglossal nerve originate from the intracranial portion, but they may extend extracranially. Solitary and extracranial schwannomas are extremely rare. We report a case of submandibular hypoglossal schwannoma along with its clinical course and management.     

Body fat standards and individual physical readiness in a randomized Army sample: screening weights,methods of fat assessment,and linkage to physical fitness

Body fat standards have been used by the military services since the early 1980s to prevent obesity and motivate good fitness habits. The Army Weight Control Program has continued to undergo evaluation and incorporate improvements based on emerging scientific findings. Recently drafted revisions of Department of Defense-wide procedures address issues of consistency and validity raised by external oversight groups. This study evaluated the impact of three proposed refinements of the Army Weight Control Program. Anthropometric measurements and fitness test performance were obtained in a randomized sample of 1,038 male and 347 nonpregnant female soldiers at three Army posts. Of this sample, 11% of men and 17% of women were overweight and overfat; 6.3 and 9.8%, respectively, were currently on the Army Weight Control Program. Screening weight tables that ensure women are not inappropriately striving to meet weights more stringent than "healthy" weight (i.e., body mass index < 25 kg/m2) still correctly identified all women for evaluation for the age-specific body fat standards. Body fat estimation using more valid DoD body fat equations that include an abdominal circumference for women reduced the number of female soldiers currently classified as exceeding fat standards, coincidentally resulting in a comparable prevalence of male and female soldiers over the fat standards (12%). A body fat allowance for young soldiers who scored very well on the physical fitness test could have benefited one-fourth of the soldiers exceeding fat standards and acknowledges biological variability in body fat thresholds. Whereas this linkage may motivate fitness habits, it complicates enforcement of reasonably achievable body fat standards. The proposed changes in fat screening and measurement methods are appropriate, but the impact to health and physical readiness of the Force cannot be accurately predicted or measured because of the absence of comprehensive baseline data and tracking mechanisms.     

Anti-tumour activity and toxicity of the new prodrug 9-aminocamptothecin glucuronide (9ACG) in mice

Cancer chemotherapy is limited by the modest therapeutic index of most antineoplastic drugs. Some glucuronide prodrugs may display selective anti-tumour activity against tumours that accumulate beta-glucuronidase. We examined the toxicity and anti-tumour activity of 9-aminocamptothecin glucuronide, a new glucuronide prodrug of 9-aminocamptothecin, to evaluate its potential clinical utility. 9-aminocamptothecin glucuronide was 25-60 times less toxic than 9-aminocamptothecin to five human cancer cell lines. Beta-glucuronidase activated 9-aminocamptothecin glucuronide to produce similar cell killing as 9-aminocamptothecin or topotecan. The in vivo toxicity of 9-aminocamptothecin glucuronide in BALB/c mice was dose-, route-, sex- and age-dependent. 9-aminocamptothecin glucuronide was significantly less toxic to female than to male mice but the difference decreased with age. 9-aminocamptothecin glucuronide and 9-aminocamptothecin produced similar inhibition (approximately 80%) of LS174T human colorectal carcinoma tumours. 9-aminocamptothecin glucuronide cured a high percentage of CL1-5 human lung cancer xenografts with efficacy that was similar to or greater than 9-aminocamptothecin, irinotecan and topotecan. The potent anti-tumour activity of 9-aminocamptothecin glucuronide suggests that this prodrug should be further evaluated for cancer treatment.     

Improvement of local control of T3 and T4 nasopharyngeal carcinoma by hyperfractionated radiotherapy and concomitant chemotherapy

PURPOSE: When the primary tumor of nasopharyngeal carcinoma (NPC) is treated at the base of skull and intracranium with conventional radiotherapy, the result is generally poor. In this report, we investigated whether hyperfractionated radiotherapy (HFRT) and concomitant chemotherapy (CCT) could achieve better local control and survival in NPC patients with T3 and T4 lesions. PATIENTS AND METHODS: Forty-eight patients (11 T3 and 37 T4 NPC) were treated with HFRT and CCT. HFRT was administered at 1.2 Gy per fraction, two fractions per day, Monday-Friday for 62 fractions for a total dose of 74.4 Gy. Concomitant chemotherapy consisting of cis-diamino-dichloroplatinum (CDDP) alone or CDDP and 5-fluorouracil was delivered simultaneously with radiotherapy during Weeks 1 and 6. Adjuvant chemotherapy consisted of CDDP and 5-fluorouracil for 2 to 3 cycles and was given monthly beginning 1 month after completion of radiation. RESULTS: With a median follow-up of 57 months (range: 28-94 months), the 3-year locoregional control rate was 93%, the disease-free survival rate was 71%, and the overall survival rate was 72%. For T4 patients, the 3-year locoregional control rate was 91%, disease-free survival was 62%, and overall survival was 63%. The major acute toxicity was Grade 3 mucositis in 73% and Grade 2 weight loss in 31% of patients. Fifty percent of patients were tube fed. Most patients tolerated the combined modality treatments relatively well; 88% of patients completed their radiation treatment within 8 weeks. CONCLUSION: HFRT and CCT for T3 and T4 NPC were associated with excellent local control and improved survival. The treatment-related toxicity was acceptable and reversible. We would recommend using HFRT with CCT for advanced T-stage NPC if the three-dimensional conformal radiation planning shows a significant portion of the brainstem to be inside the treatment field.     

Mapping geographic zones of cancer risk with epigenetic biomarkers in normal breast tissue.

PURPOSE: Genetic alterations were previously identified in normal epithelia adjacent to invasive cancers. The aim of this study was to determine DNA methylation in histologically normal tissues from multiple geographic zones adjacent to primary breast tumors. EXPERIMENTAL DESIGN: First, methylation status of a 4-kb region of RASSF1A promoter was interrogated using oligonucleotide-based microarray in 144 samples (primary tumors, 47; adjacent normals, 69; reduction mammoplasty tissues, 28). Second, allelic imbalance (AI)/loss of heterozygosity (LOH) surrounding RASSF1A promoter were analyzed in 30 samples (tumors, 8; adjacent normals, 22). Third, global methylation screening of 49 samples (tumors, 12; adjacent normals, 25; reduction mammoplasty, 12) was done by differential methylation hybridization. Real-time quantitative methylation-specific PCR was used to validate the microarray findings. RESULTS: DNA methylation in the core RASSF1A promoter was low in reduction mammoplasty tissues (P=0.0001) when compared with primary tumors. The adjacent normals had an intermediate level of methylation. The regions surrounding the core were highly methylated in all sample types. Microsatellite markers showed AI/LOH in tumors and some of the adjacent normals. Concurrent AI/LOH and DNA methylation in RASSF1A promoter occurred in two of six tumors. Global methylation screening uncovered genes more methylated in adjacent normals than in reduction mammoplasty tissues. The methylation status of four genes was confirmed by quantitative methylation-specific PCR. CONCLUSIONS: Our findings suggest a field of methylation changes extending as far as 4 cm from primary tumors. These frequent alterations may explain why normal tissues are at risk for local recurrence and are useful in disease prognostication.     

Estrogen blocks parathyroid hormone-stimulated osteoclast-like cell formation in modulating differentiation of mouse marrow stromal cells in vitro.

BACKGROUND AND PURPOSE: During skeletal development and bone remodeling, bone marrow stromal cells give rise to osteoblasts and provide a critical microenvironment to support osteoclast formation. Estrogen is important for the maintenance of bone balance in adult animals by either increasing bone mass or inhibiting osteoclastic bone resorption. This study sought to determine the role that estrogen plays in coordinating osteogenic differentiation of bone marrow stromal cells and the ability of these cells to support osteoclast formation. METHODS: A conditionally immortalized mouse bone marrow stromal cell line, MS1, was used to examine the effects of estrogen on stromal cell differentiation and on stromal cell-supported osteoclast formation. RESULTS: On treatment of MS1 cells with 17 beta-estradiol (E2) (10(-12)-10(-8) M), alkaline phosphatase activity and bone nodule formation were increased in a dose-dependent manner, while the proliferation of MS1 cells was dose-dependently inhibited. 17 beta-E2 (10(-12)-10(-8) M) also caused a concentration-dependent inhibition of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cell (MNC) formation in parathyroid hormone (PTH)-stimulated MS1 and spleen cell cocultures. Furthermore, estrogen pretreatment of MS1 cells also decreased the number of TRAP-positive MNCs in cocultures. Culturing in PTH-treated conditioned media did not rescue the loss of activity supporting osteoclast-like cell formation in MS1 cells. CONCLUSION: These results indicate that 17 beta-E2-stimulated osteoblastic differentiation of mouse marrow stromal cells results in bone matrix mineralization and a decrease in activity of supporting PTH-induced osteoclast-like cell formation.