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The tibia of each leg of the locust is moved by two antagonistic muscles, the extensor and flexor tibiae. A variety of sense organs on and in each leg provide feedback about this joint's position and movement and about forces acting on the exoskeleton and muscles. One such organ is a muscle tension receptor found within the flexor tibiae muscle of the mesothoracic leg. We now show that an apparently homologous multipolar receptor is present in the hind leg, but that here it is associated with a specialised flexor muscle, the accessory flexor. This muscle comprises 13 fibres, innervated by five of the thirteen motor neurones that innervate the main flexor muscle and, since these are slow motor units, the response properties of the receptor are constrained. The multipolar receptor attaches to the muscle fibres near their proximal insertion onto the femoral cuticle. It generally has four primary dendrites, which do not branch extensively within the muscle. We show that the receptor responds strongly to active, isometric contractions but only poorly to imposed changes of accessory flexor muscle length (i.e. passive changes in tibial position). It does not respond to tension generated by the main flexor muscle or by the extensor muscle. The tension receptor causes short-latency (0.9­1.8 ms) excitatory inputs onto the three common inhibitory motor neurones and longer-latency (3.7­8.1 ms) inhibitory inputs onto the slow extensor tibiae motor neurone. In quiescent animals, it causes excitatory inputs onto flexor tibiae motor neurones (2.2­3.8 ms) but, in more active animals, its inputs onto these neurones are often inhibitory, with delays of 6­10 ms. The slow nature of the accessory flexor muscle and the pattern of central connections of the receptor suggest that together they are involved in the control of slow movements or posture, potentially acting through a servomechanism.

The chordotonal organ at the femorotibial joint of a locust hind leg monitors extension and flexion movements of the tibia. During evoked or imposed movements of this joint the central terminals of afferent neurons from the chordotonal organ receive depolarizing, inhibitory synaptic inputs. The afferent spikes are therefore superimposed on these depolarizing IPSPs, which are generated indirectly by other afferents from the same organ that respond to the same movement. Each afferent spikes preferentially to particular features of a joint movement, and its synaptic input is typically greatest at the joint position or during the movement that generates its best response. Afferents that respond to only one direction of movement receive synaptic inputs either during movements in both directions, or only during movements in their preferred direction. Phasic velocity-sensitive afferents receive either phasic inputs during movements, or tonic inputs at new sustained joint positions, or both. The spikes of tonic position-sensitive afferents are superimposed on synaptic inputs that are dependent on joint position. The synaptic inputs sum but do not themselves evoke antidromic spikes in the afferent terminals. They reduce the amplitude of orthodromic afferent spikes by 12-28%, and this is accompanied by a reduction of up to 50% in the amplitude of monosynaptic EPSPs evoked by an afferent in postsynaptic leg motor neurons. These interactions suggest that a local gain control mechanism operates between the afferents of this proprioceptor. Thus, the effectiveness of the output synapses of an individual afferent is regulated by the network action of other chordotonal afferents that respond to the same movement.

This report describes an inexpensive ramp generator which produces multiple ramp-and-hold stimuli ("staircase-type" wave forms). The output voltage is analogue and is, therefore, free of stepping artifacts characteristic of digital function generators. When coupled with a standard power amplifier and mechanical vibrator, this system is particularly suitable for stimulation of mechanoreceptive sense organs. Connection to the serial port of an IBM personal computer, or the user port of a BBC computer allows complex ramp-and-hold sequences to be developed and repeated. The number, duration and sign of ramps, and the duration of intervening hold periods can be set using the computer. This system has been used successfully to characterise phasic and tonic neurones in the locust metathoracic femoral chordotonal organ (a leg position and movement detector).

A comparative retrospective study, based on clinical assessment and questionnaire analysis, of 97 patients treated by cryosurgical haemorrhoidectomy and 99 patients treated by Milligan-Morgan haemorrhoidectomy, at 4-year average follow-up, has shown that 70 per cent of patients in each group derived complete and lasting relief from their symptoms. Two patients in each group required further treatment. There was no significant difference between the numbers who remembered severe, moderate or mild pain, or in its duration, although fewer cryosurgical patients required opiates. Postoperative discharge ceased in 70 per cent of patients within 2 weeks. When skin tags remained, they were usually inconsequential. Anal stenosis following cryohaemorrhoidectomy did not occur, and has not been reported. Cryohaemorrhoidectomy gave results equal to Milligan-Morgan haemorrhoidectomy in patients with prolapsing piles, with fewer complications, and has the economic advantages of less time in hospital (P less than 0.01) and less time off work (P less than 0.01).

Twenty-five patients with residual tumour after resection of a primary gastric cancer were randomized to receive either 5-Fluorouracil or BCNU postoperatively or kept under close observation. Some patients receiving chemotherapy may have benefited by a delay in progression of their disease but this was short lived and subsequently all but one patient has died within a 4-year period of follow-up. There does not seem to be any advantage in treating patients who have residual gastric cancer with 5-FU and BCNU therapy.

In 39 patients with advanced colorectal cancer and no previous chemotherapy, treatment with chlorozotocin was associated with a 5% objective response rate and a median survival of 19 weeks. All of the responses occurred in patients with rectal tumors. Mild gastrointestinal symptoms affected 64% of the patients after treatment, but bone marrow suppression was not evident. Chlorozotocin is not effective against colorectal cancer when used as a single agent given as an iv bolus at doses of 120 mg/m2 (30 patients) and 150 mg/m2 (nine patients). However, further studies using a higher dose might be worthwhile.

A real-time signal averaging and harmonic analysis technique for low audio frequency waveforms is described that, although based on based on earlier software emulations of lock-in detection instruments, eliminates problems inherent in the earlier systems. Parallel processing is employed between a data acquisition minicomputer (HP-2116B) and a microcomputer (Z-80) to (1) replace an earlier chopper-type lock-in algorithm with a coherent Fourier transform, (2) digitally produce a pure (0.01% THD) modulation sine wave, (3) simplify system tune-up, and (4) produce a high-quality, flicker-free, real-time display of the averaged waveform and its harmonic content.

A survey was undertaken of 558 men with duodenal ulcer who had been treated ten to 16 years previously by truncal vagotomy and drainage, truncal vagotomy and antrectomy and subtotal gastrectomy. Of the 558, 65 had died and 111, presumed living, could not be traced, leaving 382 available for assessment. Between 75 and 85% of the traced patients were considered to have an excellent or very good result, which is a slight improvement on the previously published results in this same group of patients at five to eight years follow-up. Some of the side effects of operation had diminished slightly in frequency and there had been no significant increase in the incidence of recurrent ulceration since the previous survey. Anemia was an uncommon finding. As between the various forms of operation, truncal vagotomy and antrectomy and subtotal gastrectomy demonstrated significantly better protection against proven recurrent ulcer than did truncal vagotomy and pyloroplasty (p less than 0.05). Compared with truncal vagotomy and gastroenterostomy, however, the results of both resection operations, though better, did not achieve statistical significance at p - 0.5 level (p less than 0.1). In regard to Visick gradings the resection procedures had better scores, but the differences were not significant at the p - 0.05 level, except for vagotomy and antractomy as compared with vagotomy and pyloroplasty. But it is stressed that in formulating a policy of surgical therapy for duodenal ulcer the greater inherent immediate risks of resection operations need to be borne in mind.

From January 1963 to December 1965 inclusive 192 men with duodenal ulcer were treated by elective truncal vagotomy and pyloroplasty with one death. Ten subsequent deaths were due to causes unrelated to the ulcer or operation, and 17 patients became untraceable. The remaining 164 patients have been followed up for five to eight years. The late results have been compared with those obtained in a previous study of patients five to eight years after truncal vagotomy and gastroenterostomy, truncal vagotomy and antrectomy, and subtotal gastrectomy respectively for duodenal ulcer.Of the various postgastric operation syndromes early dumping, late dumping, bilious vomiting, and diarrhoea were all less frequent, but not significantly so, after vagotomy and pyloroplasty than after vagotomy and gastroenterostomy.Recurrent ulceration was commoner after vagotomy and pyloroplasty than after all the other operations, the incidence of proved and suspected recurrent ulcers being respectively 6.7 and 7.3% after vagotomy and pyloroplasty, but only 2.5 and 5.9% after vagotomy and gastroenterostomy, 0 and 5.2% after vagotomy and antrectomy, and 0.9 and 3.7% after subtotal gastrectomy. The differences between vagotomy and pyloroplasty and vagotomy and antrectomy or subtotal gastrectomy are statistically significant, but those between vagotomy and pyloroplasty and vagotomy and gastroenterostomy are not.Overall assessment (Visick grading) of the outcome gave poorer results after vagotomy and pyloroplasty than after any other operation, with 14% of category IV cases after vagotomy and pyloroplasty, 11% after vagotomy and gastroenterostomy, 8% after vagotomy and antrectomy, and 6% after subtotal gastrectomy-differences that are significant between vagotomy and pyloroplasty and vagotomy and antrectomy or subtotal gastrectomy but not between vagotomy and pyloroplasty and vagotomy and gastroenterostomy.In the light of these findings it is suggested that truncal vagotomy and pyloroplasty has not lived up to expectations and its place as the currently most popular procedure in the elective surgical treatment of duodenal ulcer should be reconsidered.