NK cell proliferation and inflammation

Considerable progress has been made in recent years in understanding the biology of NK cells. NK cells are no longer 'null cells', but express an array of functionally important molecules with which they mediate and regulate their cytolytic activity and the cytokines they secrete. Activation and proliferation of NK cells in influenced by cytokines produced by activated monocytes (IL-15, IL-12, IL-10) and activated T cells (IL-2). This paper reviews the phenotype and effector functions of NK cells, their tissue distribution, and evidence that NK cells proliferate in vivo as part of productive or pathologic consequences of immunity.     

Sensitivity analysis of initial value problems with mixed odes and algebraic equations

An efficient method is described for sensitivity analysis of nonlinear initial value problems, which may include algebraic equations as well as ordinary differential equations.The linearity of the sensitivity equations is utilized to solve them directly via the local Jacobian of the state equations. The method is implemented with the implicit integrator DASSL and is demonstrated on a stiff industrial reaction model.     

Increased synthetic peptide specificity of tissue-CSF bound anti-MBP in multiple sclerosis

Free and bound hydrosoluble protein extracts were prepared from four anatomical areas of a multiple sclerosis (MS) cerebrum and from corresponding anatomical areas of a normal (non-MS) control. Increased levels of IgG and anti-myelin basic protein antibodies (anti-MBP) were detected in all MS samples and they were undetectable in the controls. IgG and anti-MBP from free (unbound) hydrosoluble protein extracts are defined as free IgG and free anti-MBP while IgG and anti-MBP from tissue bound protein extracts are defined as bound IgG and bound anti-MBP. IgG was purified from free protein extracts by protein G Sepharose affinity chromatography and anti-MBP was further isolated from purified IgG by antigen specific (MBP) Sepharose affinity chromatography. Free and bound anti-MBP were reacted with 20 synthetic peptides of human MBP prepared by the Fmoc method. Free anti-MBP, whether in the context of whole protein extracts, or as purified IgG or as purified antibody was completely neutralized by peptides #12, #15, #56 and #56* containing overall residues 75-106, partially neutralized by peptides #27, #16 and #21 containing overall residues 61-83 and did not react with the remaining 13 peptides. Tissue bound anti-MBP was completely neutralized only by peptides #12, #15, #56 and #56* (overall residues 75-106) and showed no reactivity towards the remaining 16 peptides including peptides #27, #16 and #21. Synthetic peptide specificity of free anti-MBP purified from MS cerebrum was identical to previously reported specificity of free anti-MBP from MS cerebrospinal fluid (CSF), while tissue bound anti-MBP, as well as bound anti-MBP from CSF had a more restricted synthetic peptide specificity than free anti-MBP. This suggests that the most likely epitope of anti-MBP is located between residues 84 and 95 of human MBP just proximal to the tri-proline sequence (99-101).     

Cortical implants for the blind

Arrays of stimulating electrodes can be placed in the brain itself, in the visual cortex, to bring vision to the profoundly blind. However, when designing such devices one needs to take into consideration the fact that the visual pathway maps images onto cortical structures in a complex and unpredictable way     

Mathematical modelling of a reverse flow reactor with catalytic surface dynamics

This paper studies a system of partial differential equations modelling the behaviour of a reverse flow reactor. For the parameters appropriate for the oxidation of ammonia on a Pt/Al₂O₃ catalyst in a typical laboratory set-up, the reactor may be split into regions where approximate formulas that determine its behaviour are deduced. Numerical calculations are presented and can be used to compare with the analytical formulas. The physical insight gained from the asymptotic analysis suggests a new switching strategy which is the subject of numerical experiments. The switching strategy is found to be efficient at minimising the ammonia exiting the reactor after reversal.     

A novel zinc finger cDNA with a polymorphic pentanucleotide repeat (ATTTT)n maps on human chromosome 19p

PURPOSE: To evaluate the therapeutic effectiveness of a combined chemoradiotherapy program, followed by surgery in selected cases, in Stage III non-small cell lung cancer. METHODS AND MATERIALS: Between August 1988 and February 1990, 43 patients Staged IIIa-b (UICC 1987, 58% IIIb) have been treated with concomitant chemotherapy (cisplatin 15 mg/m2 and VP16 75 mg/m2, 5 days a week on week 1 and 5) and radiotherapy (40 Gy split course, 2 Gy/day on week 1, 2, 5, and 6), followed by attempted curative thoracotomy or more cycles of full dose chemotherapy with the same two drugs. RESULTS: Planned chemoradiotherapy has been given to 91% of patients; 13/43 patients have been operated, with 12 complete resections and three (7%) pathological complete responses. Toxicity was significant, with two postoperative deaths and two fatal radiation pneumonitis. Crude progression-free survival rate is 21% at 30 months, with nine patients (21%) alive and free from progression at follow-up times ranging from 31 to 49 months. Subset survival analysis showed a possibly greater therapeutic effect for non-squamous histology as compared to squamous carcinoma. CONCLUSION: These results are encouraging in a cohort of patients with quite advanced disease (58% Stage IIIb).