Broad neutralization by a combination of antibodies recognizing the CD4 binding site and a new conformational epitope on the HIV-1 envelope protein

Two to three years after infection, a fraction of HIV-1-infected individuals develop serologic activity that neutralizes most viral isolates. Broadly neutralizing antibodies that recognize the HIV-1 envelope protein have been isolated from these patients by single-cell sorting and by neutralization screens. Here, we report a new method for anti-HIV-1 antibody isolation based on capturing single B cells that recognize the HIV-1 envelope protein expressed on the surface of transfected cells. Although far less efficient than soluble protein baits, the cell-based capture method identified antibodies that bind to a new broadly neutralizing epitope in the vicinity of the V3 loop and the CD4-induced site (CD4i). The new epitope is expressed on the cell surface form of the HIV-1 spike, but not on soluble forms of the same envelope protein. Moreover, the new antibodies complement the neutralization spectrum of potent broadly neutralizing anti-CD4 binding site (CD4bs) antibodies obtained from the same individual. Thus, combinations of potent broadly neutralizing antibodies with complementary activity can account for the breadth and potency of naturally arising anti-HIV-1 serologic activity. Therefore, vaccines aimed at eliciting anti-HIV-1 serologic breadth and potency should not be limited to single epitopes.     

DR and DQ beta cDNA sequences associated with a DR2 haplotype

Three cDNA clones encoding a DQ beta and two DR beta polypeptides have been isolated and sequenced from an American black individual expressing a DR2,DQw1 haplotype. The sequences of the cDNA clones are identical to previously described DR and DQ sequences from a DR2,Dw2 cell. The differences between DQw1-associated beta chains from DR2 and DR1 haplotypes is substantial, although a DQw1-specific sequence can be identified. The identical DQ and DR beta sequences found in unrelated individuals from different racial backgrounds suggests that class II structural polymorphism within the human population will be limited.     

Tumour-cytolytic human monocyte-derived macrophages: a simple and efficient method for the generation and long-term cultivation as non-adherent cells in a serum-free medium.

We report a simple and efficient culture procedure for the generation of tumour-cytolytic human monocyte-derived macrophages (MAC). In this method, normal human peripheral blood mononuclear cells, isolated using a conventional Ficoll-Hypaque density gradient procedure, are cultured as a heterogenous leukocyte population in Teflon or other hydrophobic cultureware, in a commercially available serum-free culture medium (M-SFM) that has been formulated specifically for the cultivation and ex vivo stimulation of human monocytes and MAC, and in the absence of exogenous mitogens, antigens, cytokines or other stimulants. This procedure features a negative-selection technique that takes advantage of the differential survival of blood leukocytes. Using the prescribed in vitro conditions, lymphocytes survived relatively poorly, whereas monocytes differentiated in the absence of exogenous stimulants into mature tumour-cytolytic MAC. The MAC were present as non-adherent, single cells that expressed good viability (greater than 95%) for a prolonged period (greater than 60 days). When compared to conventional procedures for generating MAC, the prescribed technique is thought to offer several important advantages in that it: (a) eliminates the tedious and cumbersome monocyte isolation procedures, thus providing a significant savings not only in time and money but also in eliminating repetitive cell manipulations that have often been associated with damage to monocyte morphology and/or function; (b) reduces the loss of monocyte subsets that are not recovered during specific isolation procedures; (c) facilitates harvesting a single cell, non-adherent suspension of immunocompetent MAC suitable for various examinations including analyses defining MAC morphology, cytochemistry, phenotype and function; and (d) eliminates variability and artifacts associated with different sera that are utilised frequently as medium supplements. The utility of the prescribed method is illustrated by the results of ongoing studies in which scanning electron microscopy and confocal laser scanning microscopy are being used to define MAC function in different immunological reactions, and examples of these observations are presented herein.     

The analgesic effects of perioperative gabapentin on postoperative pain: a meta-analysis

BACKGROUND AND OBJECTIVES: Gabapentin is an anticonvulsant that has been shown to be effective in the treatment of neuropathic and inflammatory pain in animal and human studies. The analgesic effect of its perioperative use has not been fully elucidated. METHODS: This systematic review (meta-analysis) included 12 randomized controlled trials of 896 patients undergoing a variety of surgical procedures that investigated the impact of perioperative administration of gabapentin on postoperative outcome. RESULTS: The pooled visual analog scores for pain at 4 hours and 24 hours were significantly less in those patients who received gabapentin (weighted mean difference [WMD] = -1.57; 95% confidence interval [CI], -2.14 to -0.99 and WMD = -0.74; CI, -1.03 to -0.45, respectively). A concomitant decrease in opioid usage by those patients who received gabapentin was also noted (odds ratio [OR] = -17.84; CI, -23.50 to -12.18). Gabapentin administration was associated with sedation and anxiolysis (OR = 3.28; CI, 1.21-8.87) but not associated with a difference in lightheadedness, dizziness, nausea, or vomiting. CONCLUSIONS: Based on this systematic review, perioperative oral gabapentin is a useful adjunct for the management of postoperative pain that provides analgesia through a different mechanism than opioids and other analgesic agents and would make a reasonable addition to a multimodal analgesic treatment plan.     

Hereditary angioedema

Although the condition is rare, patients with hereditary angioedema often present because of abdominal pain or airway compromise. A 27-year-old woman presented to the emergency department in acute abdominal distress. Identification of the disease in this patient allowed for proper management and avoidance of invasive procedures. Pathophysiology, clinical manifestations, diagnosis, and therapy of hereditary angioedema are discussed.     

Evaluation of a rapid theophylline test strip assay in the emergency department setting

Test strips recently have become available to measure theophylline levels. One such test strip (AccuLevel) had not been tested in an actual clinical situation with nontechnician personnel. We prospectively evaluated the test strip on consecutive emergency department patients, comparing it with the agglutination inhibition method used by our hospital laboratory. Nurses and medics who ran the test were given only a brief demonstration and explanation of the manufacturer's instructions. The 61 test strip levels correlated highly with the laboratory results (r = 0.92, slope = 0.89, y-intercept = 0.99). The test strip results were available in less time (mean of 0.51 hours vs 1.89 hours for the laboratory, P less than .0001). The most accurate readings were obtained by those who ran the test most frequently. Caffeine intake did not influence the test. Cost was significantly lower than charges at local hospitals.