Detecting in vitro anthelmintic effects with a micromotility meter

An in vitro target parasite anthelmintic assay utilizing a micromotility meter has been developed and validated. Haemonchus contortus, an economically important ruminant helminth with worldwide distribution, was the parasite used in the model. Four commercially available ruminant anthelmintics (albendazole, ivermectin, levamisole hydrochloride and coumaphos) were initially evaluated at concentrations of 200, 150, 100 and 50 micrograms ml-1. All four significantly affected helminth motor activity and were active at 200 and 150 micrograms ml-1, and three of the four were active at 100 and 50 micrograms ml-1. An Upjohn compound (p-toluoyl chloride phenylhydrazone) was also assayed and was significantly active at all four levels. In a subsequent titration study, albendazole, levamisole hydrochloride, ivermectin and the hydrazone were significantly active at 100 and 10 micrograms ml-1; only levamisole hydrochloride and the hydrazone were active at 1.0 microgram ml-1. None of the drugs were active at 0.1 microgram ml-1. The data indicate that the in vitro H. contortus assay utilizing the micromotility meter is sensitive, accurate, rapid, repeatable, and inexpensive. With additional effort, this model can be extended to incorporate other target helminth parasites and stages of development. This in vitro assay system should be a valuable addition to the battery of tests used to identify anthelmintic candidates, monitor drug resistance, and define the kinetics and mode of action of drugs.

Pharmacokinetics and effects on the renin-angiotensin system of ramipril in elderly patients

Converting enzyme inhibitors are likely to be prescribed with increasing frequency in elderly patients. The pharmacokinetics of ramipril, a new potent long-acting non-sulphydryl converting enzyme inhibitor, and its effects on blood pressure, plasma renin activity and angiotensin II concentrations were studied in a group of 8 elderly volunteers (mean age 77, range 61 to 84). Circulating concentrations of the active diacid formed from its parent drug were consistently higher in this group despite apparently normal renal function, assessed by serum creatinine and urea concentrations, compared with younger volunteers (age range 21 to 30). The initial dose of ramipril should be lower in older subjects. The study emphasizes the importance of careful extrapolation of data obtained from young volunteers to older subjects.

Improved survival of the diabetic foot: the role of a specialized foot clinic

A specialized foot clinic for diabetic patients has made a detailed analysis of the presentation of diabetic foot ulcers and from this a new, organised approach to treatment has been derived. Over three years it has achieved a high rate of ulcer healing and reduced the number of major amputations. It has brought together the skills of chiropodist, shoe-fitter, nurse, physician and surgeon to manage the distinctive lesions of the neuropathic and ischaemic diabetic foot. The neuropathic ulcer was invariably associated with callus, whereas the ischaemic ulcer presented as areas of necrosis often from localised pressure of tight shoes. Essential aspects of management are specially constructed shoes, intensive chiropody and precise antibiotic treatment. Healing was achieved in 204 out of 238 (86 per cent) neuropathic ulcers and 107 out of 148 (72 per cent) ischaemic ulcers. Relapse rate in special shoes was 26 per cent compared with 83 per cent who preferred to wear their own shoes. In the two years before the establishment of the clinic, there were 11 and 12 major amputations yearly. This rate has now been reduced to seven, seven and five amputations yearly.

Hodgkin's disease: is there a price for successful treatment? A 25-year experience

Three hundred-twenty patients with Hodgkin's disease (HD) were studied retrospectively to assess the impact of treatment on survival and the development of second malignant neoplasms (SMN). All stages of HD were considered. Treatment groups included XRT only, XRT + multiagent chemotherapy (MAC), XRT + single agent chemotherapy (SAC), and chemotherapy only (Chemo). MAC was subdivided into MOPP and non-MOPP regimens. Twenty-one patients developed 23 SMN, only two of which were acute leukemias. Survival was greatest for XRT only because of a large proportion of early stage HD in this group. SMN were seen in all treatment groups except Chemo only. The XRT + MAC group had a significantly elevated observed-to-expected ratio for SMN, but it was difficult to attribute this to either MOPP or non-MOPP due to very small numbers of patients. The actuarial risk of SMN for both MOPP and non-MOPP rises dramatically between 10 and 15 years, however, extrapolation cannot be done, again because of very small numbers. We conclude that there is an increased risk of SMN in patients treated aggressively for HD, but that the exact cause of SMN is difficult to determine.

Heparin and dihydroergotamine prophylaxis against thrombo-embolism after hip arthroplasty

A prospective study involving 500 consecutive patients undergoing hip replacement was performed to find out whether a combination of heparin and dihydroergotamine was effective in preventing postoperative fatal and non-fatal emboli. Deep-vein thrombosis was demonstrated in 131 cases (26.2%), in 99 of whom thrombi were confined to the ipsilateral (operated) limb and in 13 to the contralateral limb; 19 patients developed bilateral thrombi. Nine patients (1.8%) died during the first four weeks after operation, before they were discharged from hospital; in one, major emboli were demonstrated in the right pulmonary artery. Three of the 500 patients developed non-fatal pulmonary emboli. Excessive bleeding occurred in 21 (4.2%) and in 19 of these prophylaxis was discontinued. Wound haematomas developed in 25 patients (5.0%); only six required evacuation but in none of these six did deep infection occur while in hospital; in three patients, however, the wound haematoma prolonged the stay in hospital. Thus the combination of heparin and dihydroergotamine proved an effective prophylaxis against pulmonary embolism in patients undergoing total hip replacement. The risk of bleeding complications is wholly acceptable when balanced against the advantages of the therapy.

Sympathetic innervation of the jejunal villus

Using fluorescent histochemical methods it has been shown that the noradrenergic nerves in the jejunal villus are associated with the capillaries underlying the basolateral membrane of the epithelium. Noradrenergic fibres were also seen to lie between the epithelial basolateral membrane and the capillaries but were never observed close to the epithelium unless accompanied by an underlying capillary. The distribution of noradrenergic fibres suggests that it is unlikely that noradrenaline diffuses directly from the varicosity to the epithelial basolateral membrane. Noradrenaline may, therefore, act on the capillary itself and in some way affect fluid absorption. However, noradrenaline released adjacent to a capillary might diffuse into the capillary to be distributed at another site along its course.

The noradrenergic innervation of the excretory ducts of the parotid, mandibular and sublingual glands in the rat

The noradrenergic innervation of the excretory ducts of the parotid, mandibular and sublingual salivary glands in the rat has been examined using fluorescence histochemistry. None of the ducts were found to be innervated directly but, in the mandibular duct, innervated blood vessels are in close proximity to the epithelial cells of the duct and it is suggested that noradrenaline may diffuse from the vascular nerve endings to receptors on the epithelial cells.

Striatal glutamatergic function: modifications following specific lesions

The effects of specific lesions of the striatum: (a) hemidecortication; (b) striatal injection of (+/-) ibotenate; and (c) 6-hydroxydopamine injections into the substantia nigra, were investigated on specific [3H]glutamate binding to striatal membranes. One month after decortication, there was a substantial reduction of calcium-dependent, stimulated glutamate release from striatal slices, indicating effective loss of glutamatergic fibres. Striatal glutamate binding increased by approximately 30% and this supersensitivity could be attributed solely to an increased receptor density. Ibotenate lesions which destroy target neurones for the glutamatergic fibres (sparing terminals), reduced glutamate binding in the striatum, as did nigral 6-OHDA lesions which delete striatal dopaminergic terminals. This finding supports the concept of there being glutamate receptors on pre-synaptic dopamine terminals in the striatum, involved in regulation of dopamine release. 6-OHDA lesions also result in a supersensitivity of the dopamine receptors localized on the cortico-striatal afferent terminals, as evidenced by the enhanced ability of dopamine to inhibit the K+-evoked, calcium-dependent release of endogenous striatal glutamate.

Sites of noradrenergic innervation of the jejunal villus

1. It has been demonstrated that the upper region of the jejunal villus is supplied with noradrenergic nerves. 2. These nerves are in close proximity to the capillary network underlying the epithelial cells and the lacteal. 3. Hitherto sympathetic innervation of the gut had not been demonstrated to extend further than the crypt region. 4. This evidence allows the proposal that the vasculature and epithelial cells may be involved in the control of absorption from the gastrointestinal tract.

Changes in cell shape and induction of cell differentiation in the protozoan Herpetomonas samuelpessoai by cholinergic drugs

Carbamylcholine, Pilocarpine and Atropine, but not Epinephrine, inhibited the motility of Herpetomonas samuelpessoai, when added to the suspension medium for 1 h. In addition, protozoan cells became spherical under the influence of atropine. This drug also induced the formation of the more differentiated opistomastigote form of the protozoan, in 60 per cent of growing cells, whereas these forms represented less than 5 per cent in untreated cultures. This may indicate that cholinergic receptors are present in this protozoan.

Noradrenergic innervation of the villi of rat jejunum

Using fluorescent histochemical methods it has been shown that the villi of the jejunum are innervated by noradrenergic fibres. Varicose fibres originating in the plexus associated with the arterioles of the submucosa run close to the central lacteal and extend to the villus tip. It is suggested that the nerves may be involved in the control of absorption although exactly which structure in the villi are innervated remains unclear.

Fractures of the radius and ulna in children

A consecutive series of 375 fractures of the radius and ulna in children of up to 15 years is described. At discharge from the fracture clinic, 65 failed to achieve a satisfactory result. After 4 years, however, only 9 children did not have normal function and only 1 was aware of any disability. The natural history of this injury is towards a complete functional recovery in the vast majority of cases.

Gritti-Stokes amputation in atherosclerosis: a review of 237 cases

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