Case report: lipoma arborescens of the sub-deltoid bursa

Lipoma arborescens is a rare synovial disorder which principally affects the knee joint. We describe an unusual case of lipoma arborescens arising within the sub-deltoid bursa in association with a rotator cuff tear. Pre-operative diagnosis was made by magnetic resonance imaging.     

Production of monoclonal antibodies using a secretion capture report web

We describe a novel method for the production of monoclonal antibodies using a secretion capture report web (SCRW). Following HAT selection in bulk culture, individual hybridomas are encapsulated in biotinylated agarose drops. Antibody secreted by the hybridoma is captured within the agarose drop using an avidin bridge and biotinylated anti-mouse immunoglobulin. The secreted antibody is detected by a fluorescent reporter which can be either a second anti-mouse antibody or an antigen. The binding of the reporter can be quantitated and the desired hybridoma directly cloned by flow cytometry. Multiparameter (i.e., two-color) reporter analysis can also be used to selectively enrich and clone rare hybridomas secreting antibodies directed to unique epitopes. The method allows the characterization of thousands of clones per second and the isolation of hundreds of clones per day.     

Recombinant protein sequences can trigger methylation of N-terminal amino acids in Escherichia coli

Recombinant human hemoglobin rHb1.1 has been genetically engineered with the replacement of the wild-type valine residues at all N-termini with methionine, an Asn 108 Lys substitution on the beta globins, and a fusion of the two alpha globins with a glycine linker. When rHb1.1 was expressed in Escherichia coli, methylation of the N-terminal methionine of the alpha globin was discovered. Another mutant has been engineered with the alpha globin gene coding for N-terminal methionine followed by an insertion of alanine. Characterization of expressed hemoglobin from this variant revealed a methylated N-terminal alanine that occurred through two posttranslational events: initial excision of the N-terminal methionine, followed by methylation of alanine as the newly generated N-terminus. No methylation was observed for variants expressed with wild-type valine at the N-terminus of the alpha globin. The methylation of N-terminal amino acids was attributed to a specific protein sequence that can trigger methylation of proteins expressed in E. coli. Here we demonstrate that proline at position 4 in the protein sequence of alpha globin seems an essential part of that signaling. Although N-terminal methylation has been observed previously for native E. coli proteins with similar N-terminal sequences, methylation of the recombinant globins has allowed further delineation of the recognition sequence, and indicates that methylation of heterologous proteins can occur in E. coli.     

The effect of dilute vasopressin solution on blood loss during operative hysteroscopy: a randomized controlled trial

OBJECTIVE: To assess the effect of intracervical injection of dilute (0.05 U/mL) vasopressin solution on blood loss during operative hysteroscopy. METHODS: In a randomized, double-blind study, dilute vasopressin solution or placebo (normal saline) was injected into the cervical stroma of 106 women before dilation of the cervix in preparation for operative hysteroscopy. Intraoperative bleeding was calculated by dividing the number of red blood cells per milliliter of outflow distention fluid by the number of red blood cells per milliliter of the woman's blood immediately before the procedure and multiplying this quotient by the total amount of outflow fluid collected. Pressures were kept constant with a hysteroscopic infusion pump. RESULTS: The mean (+/-standard error of the mean) intraoperative blood loss of the treated (vasopressin) and control (placebo) groups was 20.3 +/- 4.1 mL (range 0-135) and 33.4 +/- 5.4 mL (range 0-290), respectively. The volume of distention fluid intravasation in the treated and control groups was 448.5 +/- 47.0 mL (range 30-1410) and 819.1 +/- 79.7 mL (range 20-1977), respectively. The operating time in the treated and control groups was 31.1 +/- 1.2 minutes (range 18-52) and 34.1 +/- 1.3 minutes (range 19-65), respectively. For all three outcome measures, the differences between the two groups were statistically significant, but for visual clarity of the uterine cavity during surgery, the difference was not significant. CONCLUSION: Administration of dilute vasopressin solution (0.05 U/mL) to the cervical stroma significantly reduces blood loss, distention fluid intravasation, and operative time during hysteroscopy. Further evaluation is required to determine the optimum dosage.     

Effect of mu-opioids morphine and buprenorphine on the development of adjuvant arthritis in rats

OBJECTIVE AND DESIGN: On the basis that endogenous opioids play a role in the physiological response to inflammation, this study tests the anti-arthritic effects of a mu-opioid agonist, morphine and the partial mu-agonist, buprenorphine. MATERIAL: Male Lewis rats were used. TREATMENT: Rats were inoculated subcutaneously with 0.05 ml of Freund's complete adjuvant (5 mg/ml) into the right hind paw to produce adjuvant arthritis. Morphine (either 10 to 60 mg/kg/day s.c. bolus or 60 mg/kg/day s.c. infusion) and buprenorphine (0.65 +/- 0.06 mg/kg/day, orally), respectively, were administered for 3 days during the primary inflammatory phase of adjuvant arthritis. METHODS: The progression of adjuvant arthritis was monitored every three days by body weight change and hind limb oedema (ipsilateral and contralateral). On day 21 the animals were sacrificed and histology and radiography of the contralateral limb were performed. In rats receiving Freund's adjuvant and no drug treatment, the incidence of arthritis was 89%. Effect was expressed as the pooled severity index (PSI) derived from the arithmetic average of the volume, histology and radiography scores in the contralateral hind limb. RESULTS: Buprenorphine had no effect on experimental arthritis (PSI control vs treated: 242 +/- 28 vs 253 +/- 28%). In contrast, morphine by subcutaneous injection twice daily (10 to 60 mg/kg/day) but not by subcutaneous infusion (60 mg/kg/day) was found to attenuate the progression of adjuvant arthritis in a dose-dependent manner. This indicates that the anti-arthritic effects of morphine are opioid receptor mediated (ED50, 58 +/- 9 mg/kg) and suggests that the local concentration reached effective levels only after subcutaneous injection. It is also possible that the high doses of morphine were anti-inflammatory through effects at the kappa receptor. However, these high doses of morphine produced death in one third of the rats, the calculated lethal dose (LD50, 63 +/- 2 mg/kg) being close to the effective dose. CONCLUSION: Anti-arthritic effects of morphine are opioid receptor mediated but morphine use for this indication is restricted by its adverse effects.     

Regulative interactions in zebrafish neural crest

Zebrafish trunk neural crest cells that migrate at different times have different fates: early-migrating crest cells produce dorsal root ganglion neurons as well as glia and pigment cells, while late-migrating crest cells produce only non-neuronal derivatives. When presumptive early-migrating crest cells were individually transplanted into hosts such that they migrated late, they retained the ability to generate neurons. In contrast, late-migrating crest cells transplanted under the same conditions never generated neurons. These results suggest that, prior to migration, neural crest cells have intrinsic biases in the types of derivatives they will produce. Transplantation of presumptive early-migrating crest cells does not result in production of dorsal root ganglion neurons under all conditions suggesting that these cells require appropriate environmental factors to express these intrinsic biases. When early-migrating crest cells are ablated, late-migrating crest cells gain the ability to produce neurons, even when they migrate on their normal schedule. Interactions among neural crest cells may thus regulate the types of derivatives neural crest cells produce, by establishing or maintaining intrinsic differences between individual cells.