International scientific meetings: relation between structure and function.

Increasing pressure is being placed on the scientific community to evaluate research activities. Scientific meetings consume a small but important fraction of the research budget. Audit of a well established series of scientific meetings showed that they met their immediate objectives in that they were international and multidisciplinary and provided a forum in which all participants actively contributed to discussion. The meetings had a positive outcome for the participants, leading in many cases to the subsequent exchange of research material (60% of participants) and to the establishment of collaborative research projects (31%). The impact of the meetings on the scientific community at large was assessed by citation analysis, which showed that the proceedings were cited early, often, and over a substantial period.     

Management of patients with congenital hypothyroidism.

The biochemical state and treatment of 73 children and 44 adults up to the age of 40 with proved congenital hypothyroidism were assessed in a regional study in the north of England. The findings showed that a substantial proportion of the patients were having inappropriate treatment or were not taking their treatment regularly and that in some of these there were clinical effects.     

Screening for antimalarial maculopathy in rheumatology clinics.

Ophthalmoscopy and three tests of visual function were undertaken in 39 patients with rheumatoid arthritis receiving treatment with antimalarial drugs and in a control group of 16 patients with rheumatoid arthritis who were not receiving such treatment. Visual contrast sensitivity, macular threshold to red light, and central visual fields to red targets were not significantly different in treated patients and controls. There were no abnormalities in visual acuity, but 11 of 76 eyes of treated patients showed minor macular abnormalities on ophthalmoscopy that were not seen in control patients, suggesting that ophthalmoscopy may be the most sensitive measure of early drug toxicity. Five rheumatologists were able to identify 52 of 65 minor changes detected by an ophthalmologist. These studies, and a critical review of published reports, suggest that in clinical practice antimalarial drugs can be administered safely to patients with rheumatoid arthritis without the need for repetitive routine examination by an ophthalmologist or the use of complicated physiological tests. Recording of visual acuity in each eye and ophthalmoscopy by the prescribing doctor may be all that are required to detect early antimalarial maculopathy.     

Organic free radicals and proteins in biochemical injury: electron- or hydrogen-transfer reactions?

The reactions of organic free radicals, acting as either reductants or oxidants, have been studied by pulse radiolysis in neutral aqueous solution at room temperature. Manyhydroxyl-substituted aliphatic carbon-centred radicals and one-electron adducts have been shown to be good one-electron reductants, while several oxygen-, sulphur- and nitrogen- (but not carbon-) centred free radicals have been shown to be good one-electron oxidants. Several carbon-centred radicals can be reduced rapidly by hydrogen transfer, from undissociated thiol compounds which can thus act as catalysts facilitating the overall reduction of a carbon-centred radical by an electron-donating molecule. Kinetic considerations influenced by the one-electron redox potentials of the radical-molecule couples involved, determine whether a particular reaction predominates. In this paper examples of such reactions, involving a water-soluble derivative of vitamin E (Trolox C) and the coenzyme NADH, are described, together with studies showing (a) that even in complex multi-solute systems some organic peroxy radicals can inactiviate alcohol dehydrogenase under conditions where the superoxide radical does not, and (b) the superoxide radical can be damaging if urate is also present, and this damage can be reduced by the presence of superoxide dismutase.     

Value of routine follow up of women treated for early carcinoma of the breast.

The value of routine follow up of women treated for early breast cancer by mastectomy with or without postoperative radiotherapy was assessed retrospectively. Over eight years 546 patients made 6863 clinic visits, during which 192 first relapses were detected. Ninety three relapses were detected at scheduled (routine) visits and 99 at unscheduled (interval) visits. First relapses within the treated area or in the contralateral breast were detected significantly more commonly at routine visits than were first metastatic relapses (66/89 (74%) compared with 27/103 (26%)). Patients whose local relapse was detected at a routine visit had a significantly better survival than those whose local relapse was detected at an interval visit. A relapse that was potentially curable (local or in the contralateral breast) was detected at 66 (1%) of 6764 routine visits, but only 26 (39%) of these patients remained free of disease. It is concluded that the intensity of follow up of such patients could be reduced without any adverse effect on prognosis but with appreciable financial and other benefits.     

Effects of starvation on lung mechanics and biochemistry in young and old rats

Two groups of rats (young and old) were food-deprived for 3 wk and were compared with age-matched fed groups. Final body weight and dry and wet weights of lungs were significantly reduced in both young and old starved rats. As determined by saline volume-pressure (VP) curves, lungs of young starved rats accepted significantly less volume at all pressure levels compared with lungs of young fed rats. When expressed as a percent of maximum lung volume, the VP curve in young starved rats was significantly shifted upward at low lung volumes. In the old rats, the VP curves were similar in fed and starved rats. Total lung content of protein, DNA, crude connective tissue, hydroxyproline, and elastin were significantly reduced in young starved compared with young fed rats, whereas in old starved rats only protein and DNA contents were lower than those in old fed animals. It appears that in rapidly growing young rats starvation leads to growth retardation, loss of connective tissue components, and possibly reduction in tissue elastic forces at low lung volumes, whereas starvation has no significant effects on lung mechanics and connective tissue in old rats.     

Characterization of the Resistance to Oxygen Diffusion in Legume Nodules

A method for characterizing the resistance to oxygen diffusionin legume nodules has been developed. This is based on the assumptionsthat diffusion can be described using a simple resistance analogueand that the respiratory response of the bacteriod-containingcells to external oxygen concentrations can be analysed as adiffusion-limited process. Applying this analysis to experimentaldata from infact white clover plants allowed the total diffusionresistance to be separated into (a) a minimum resistance and(b) the extent to which this resistance can be increased. Whenthe carbohydrate status of the nodules was reduced by dark treatments,the minimum diffusion resistance increased, and after 24–28h darkness equalled the maximum resistance. At the same timethe ability to control this resistance was lost. White clover, nitrogen fixation, oxygen diffusion, nodule respiration