Manipulation of attention at study affects an explicit but not an implicit test of memory

We investigated the impact of attention during encoding on later retrieval. During study, participants read some words aloud (ignoring the print color) and named the print color of other words aloud (ignoring the word). Then one of two memory tests was administered. The explicit test--recognition--required conscious recollection of whether a word was studied. Previously read words were recognized more accurately than were previously color named words. This contrasted sharply with performance on the implicit test--repetition priming in lexical decision. Here, words that were color named during study showed priming equivalent to words that were read during study; both were responded to faster than unstudied words. Thus, an attentional manipulation during study had a strong effect on an explicit test of memory, but almost no effect on an implicit test. Focal attention during study is crucial for remembering consciously but not necessarily for remembering without awareness.     

Variation in recovery of motile sperm after preparation by a simple Percoll gradient technique

PURPOSE: Numerous techniques have been used to prepare sperm for assisted reproduction technology. Density-gradient centrifugation with Percoll is becoming a method of choice. This study reviewed the results of a simple two-layer discontinuous Percoll gradient. METHODS: We reviewed retrospectively results obtained from 208 semen specimens prepared for in vitro fertilization by a discontinuous Percoll gradient. RESULTS: Overall results (mean +/- SD) were a recovery of 21 +/- 16% of total sperm, recovery of 38 +/- 30% of motile sperm, and a motility in the final sperm preparation of 88 +/- 10%. Specimens with higher initial concentrations had higher motility in the final preparation. Higher total recovery and higher motility in the final preparation were found for specimens with a higher initial motility. CONCLUSIONS: This simple two-layer Percoll technique is rapid and inexpensive and reliably produces a final sperm preparation with desirable characteristics. Even though specimens with poor initial parameters yielded final preparations with excellent characteristics, fertilization rates were still related to the initial semen parameters.     

A pilot clinical trial of two murine monoclonal antibodies fixing human complement in patients with chronic lymphatic leukaemia

The use of monoclonal antibodies (MABs) for the therapy of malignant diseases offers the potential advantage of greater target cell specificity, and therefore less toxicity. A major limitation of this therapeutic approach has been the inability of most MABs to kill the cell once bound to the target antigen. We have previously reported the development of two murine IgM MABs, WM63 (CD48) and WM66 (unclustered), that react with panleucocyte antigens widely expressed on cells from lymphoproliferative disorders, and are lytic with human complement. These antibodies have subsequently been administered intravenously to patients with chronic lymphocytic leukaemia (CLL) in a Phase One trial. Seven patients with progressive CLL received increasing daily doses of WM66 (Patients 1-3) or WM63 (Patients 4-7), with one patient also receiving a continuous infusion of WM63 over 20 hours. All patients demonstrated a significant but transient reduction in the number of circulating leucocytes, and no overall effect on disease progression was observed. Antibody coating of circulating lymphocytes was seen in patients receiving WM-63. Patients receiving large doses of WM63 (cases 5-7) demonstrated a decline in complement levels during treatment. There were no major adverse reactions to WM66, but two patients developed dose limiting side effects to WM63. No human anti-mouse antibody (HAMA) responses were documented. These findings indicate that in vitro cytotoxicity mediated by Mabs fixing human complement correlates poorly with clinical responses, and support earlier observations which indicate that cell-mediated cytotoxicity is necessary for effective antibody therapy.     

Sensitivity and specificity of the Quetelet index to assess obesity in men and women

A refractory strain of the mosquito, Anopheles gambiae, melanotically encapsulates and destroys malaria parasites in the midgut. Normal development of parasites is observed in a closely related susceptible strain. To examine the basis for the difference in response, the two strains were compared for responses to inoculated Sephadex beads of varying charge. Negatively charged C-25 beads elicited a much stronger reaction in the refractory strain where 49% of the beads were strongly melanized by 24 h, compared with only 5% in the susceptible strain. Male mosquitoes of each strain responded similarly, with 100% of the beads strongly melanized by 24 h in the refractory strain compared with only 5% in the susceptible strain males. A time course revealed that the melanization in refractory but not susceptible mosquitoes increases substantially over time; 91% of C-25 beads were melanized in refractory females at 72 h compared with 9% in the susceptible sample. Neutral G-25 beads and positively charged A-25 beads were melanized in both strains, demonstrating that the capacity to melanize foreign particles is present in susceptible mosquitoes.     

Bicarbonate secretion in the guinea pig duodenum: functional characterization of peptide hormone receptors in duodenal enterocytes

Human peripheral blood mononuclear cells from healthy donors were treated ex vivo with the proteolytic enzyme bromelain and studied by flow cytometry. Bromelain-treated lymphocytes exhibited 60-90% reduced cell surface staining for CD44 and CD62-L molecules. While the staining for molecules CD16, CD56 and CD49d was unaffected, a moderate increase (10-40%) in expression of the beta(2)-integrins CD11a-c was seen. This selective modulation of cell adhesion molecules (CAM) was seen on T cells and NK cells, as well. The selective modulation of CAM may help explain some of the clinical effects observed after bromelain treatment in patients suffering from chronic inflammatory disease, HIV and cancer.     

Pharmacokinetics of rifampicin in gastrectomized persons (author's transl)

A laboratory method was developed whereby the presence of Rifampicin in the blood is determined microbiologically by means of a diffusion test. The organism used was Sarcina lutea. The tests established that the Rifampicin levels in the blood of pylorogastrectomized persons were significantly higher then they were in a normal control group. The daily changes in the Rifampicin levels were simulated and checked by analogue computer. The findings indicated that the increased absorption in gastrectomized persons cannot be due to accelerated passage and that it is presumably attributable to chemical and physical factors. The results are analysed statistically and summarized in graphs.     

4-nitro-2-phenoxymethanesulfonanilide (R-805): a chemically novel anti-inflammatory agent

The anti-inflammatory activity of the sulfonanilide, 4-nitro-2-phenoxymethanesulfonanilide (R-805) has been demonstrated in conventional models (carrageenan-induced edema of the rat's paw, UV-induced erythema of guinea-pig skin, adjuvant-induced arthritis of the rat). R-805 differs from most currently available acidic anti-inflammatory drugs in that its functional acidic group is not carboxyl. The relative anti-inflammatory potency of R-805 is comparable to indomethacin. Calculation of acute therapeutic indices (LD50/ED50) for 8 acidic anti-inflammatory drugs show R-805 to possess a more favourable index than the other drugs examined.