Potential for ammonia recapture by farm woodlands: design and application of a new experimental facility.

There has been increasing pressure on farmers in Europe to reduce the emissions of ammonia from their land. Due to the current financial climate in which farmers have to operate, it is important to identify ammonia control measures that can be adopted with minimum cost. The planting of trees around farmland and buildings has been identified as a potentially effective and low-cost measure to enhance ammonia recapture at a farm level and reduce long-range atmospheric transport. This work assesses experimentally what fraction of ammonia farm woodlands could potentially remove from the atmosphere. We constructed an experimental facility in southern Scotland to simulate a woodland shelterbelt planted in proximity to a small poultry unit. By measuring horizontal and vertical ammonia concentration profiles within the woodland, and comparing this to the concentration of an inert tracer (SF6) we estimate the depletion of ammonia due to dry deposition to the woodland canopy. Together with measurements of mean ammonia concentrations and throughfall fluxes of nitrogen, this information is used to provide a first estimate of the fraction of emitted ammonia that is recaptured by the woodland canopy. Analysis of these data give a lower limit of recapture of emitted ammonia, at the experimental facility, of 3%. By careful design of shelterbelt woodlands this figure could be significantly higher.

Pharmacological characterisation of melatonin mt1 receptor-mediated stimulation of [35S]-GTPgammaS binding.

The activation of G-proteins by melatonin mt1 receptors was studied by measuring [35S]-guanosine-5'-(3-thiotriphosphate) ([35S]-GTPgammaS) binding to membranes prepared from Chinese hamster ovary (CHO) cells stably expressing human mt1 receptors. Melatonin stimulated [35S]-GTPgammaS binding in a concentration-dependent manner (pEC50, 8.77+/-0.02). The optimal (212+/-4%) increase over basal levels of binding (basal = 100%) was observed following incubation of membranes (12.5 microg protein/well) for 120 min at 30 degrees with [35S]-GTPgammaS (0.1 nM), in the presence of GDP (10 microM), NaCl (100 mM), and MgCl2 (10 mM). Melatonin analogues stimulated [35S]-GTPgammaS binding with a rank order (2-iodomelatonin > melatonin = S20098 > GR196429 > 6-chloromelatonin = 6-hydroxymelatonin >> N-acetylserotonin > or = GR135531 = mt1 luzindole = 5-HT = 0), which was identical to their affinities for the high affinity state of the receptor (correlation coefficient 0.94). All agonists evoked similar maximum increases in [35S]-GTPgammaS binding. EC50 values were 14- to 63-fold lower than binding affinities. The melatonin receptor antagonist luzindole (0.1-10 microM) evoked a parallel rightward shift in the melatonin concentration-response curve, with a pKB of 7.19+/-0.13, which is similar to its affinity in radioligand binding studies for human mt1 receptors. Stimulation of [35S]-GTPgammaS binding was abolished by pretreatment of cells with pertussis toxin (18 hr, 100 ng/mL) prior to preparation of membranes. Melatonin was without effect in CHO cells which lacked the mt1 receptor. Thus, melatonin and melatonin analogues stimulate [35S]-GTPgammaS binding with a profile which is consistent with binding to mt1 receptors causing activation of Gi/Go G-proteins.

Stem growth reduction in mature Sitka spruce trees exposed to acid mist.

An eighteen-year-old clone of Sitka spruce (Picea sitchensis (Bong.) Carr) growing in the field was used to evaluate the whole tree response of 'mature' Sitka spruce to acid mist treatment. The mist, an equimolar mixture of H(2)SO(4) and NH(4)NO(3) at pH 2.5 with or without particles (soda glass ballotini < 20 microm diameter), was applied twice weekly (equivalent to 4 mm precipitation week(-1)) throughout the growing season, May-November 1990-1992. The annual dose of S, N, H applied as mist (at 51, 48 and 3.3 kg ha(-1), respectively) was 2.5 times that measured in the Scottish uplands. Throughout the experiment there was no evidence of visible injury symptoms, yet there was a highly significant reduction (p < 0.02) in the stem-area increment relative to the stem area at the start, measured using vernier dendrometer bands. There was no significant difference between the (acid mist + particle) and the acid mist only treatments. The mean relative stem-area increment over two complete growing seasons (1991-1992) was 65% for control trees, but only 53% for acid-misted trees.

The anxiolytic-like activity of GR159897, a non-peptide NK2 receptor antagonist, in rodent and primate models of anxiety.

The non-peptide NK2 receptor antagonist, GR159897, was evaluated in two putative models of anxiety, the mouse light-dark box and the marmoset human intruder response test. Effects were compared to the structurally dissimilar NK2 antagonist, (+/-) SR48968 and the benzodiazepines, diazepam and chlordiazepoxide. GR159897 (0.0005-50 micrograms/kg SC) caused significant and dose-dependent increases in the amount of time mice spent in the more aversive light compartment of the light-dark box, with no effect on locomotor activity. (+/-)SR48968 (0.0005-0.5 microgram/kg SC) and diazepam (1-1.75 mg/kg SC), also increased time spent in the light compartment, without effect on locomotor activity. In the marmoset human intruder response test, GR159897 (0.2-50 micrograms/kg SC) significantly increased the amount of time marmosets spent at the front of the cage during confrontation with a human observer ("threat"). Similar effects were produced by (+/-)SR48968 (10-50 micrograms/kg SC) and chlordiazepoxide (0.3-3.0 mg/kg SC). These results provide further evidence, in both rodent and primate species, for the ability of NK2 antagonists to restore behaviours which have been suppressed by novel aversive environments. Such effects indicate that NK2 antagonists may have anxiolytic activity.

Plaster of Paris splintage for the hand: volar or dorsal?

The effectiveness of a volar or a dorsal plaster of Paris slab for splinting a hand in the 'safe' position was studied prospectively. Seventy-two splints, comprising 36 dorsal and 36 volar, were applied. Measurements of the metarcarpophalangeal joint angle and the proximal interphalangeal joint angle on the lateral radiograph revealed the volar splint to be significantly more consistent in securing the proximal interphalangeal joint angle at less than 15 degrees. There was no significant difference between volar or dorsal splints for the metarcarpophalangeal joint angle. As the volar splint was also subjectively more comfortable, its use is recommended.

Anxiolytic activity of tachykinin NK2 receptor antagonists in the mouse light-dark box.

The tachykinin NK2 receptor antagonists, GR100679 (0.02-200 micrograms/kg s.c.) and (+/-)-SR489698 (0.05-5.0 micrograms/kg s.c.), dose-dependently increased the time which mice spent in the light side of the light-dark box. There was no evidence of sedation or other over behaviours. The amplitudes of these effects were similar to that evoked by diazepam (1.75 mg/kg s.c.). These results indicate a disinhibitory action of NK2 antagonists on suppressed behaviours in a novel aversive environment. This suggests an involvement of NK2 receptors in anxiety-related behaviours.

Nonunion of a pathologic juvenile scaphoid fracture after osteomyelitis.

A patient with osteomyelitis of the scaphoid in childhood resulting in a pathologic fracture with nonunion is presented. This ununited fracture of the scaphoid was successfully grafted eight years later with a satisfactory outcome.

Extensor indicis proprius transfer for rupture of the extensor pollicis longus tendon.

We reviewed 21 patients with 22 ruptures of the extensor pollicis longus at a mean of 5.3 years after transfer of the extensor indicis proprius tendon. Of these, 19 with 21 transfers described the result as good, and two as fair. The mean deficit of extension between the operated and unoperated thumbs was 1.4 cm, and the mean flexion deficit 0.6 cm. Pressure gauge measurements showed that the strength of the transfer was 51% of that of the uninjured extensor. The two fair results had an extensor lag of over 1.5 cm. Independent extension of the index was maintained in all patients, none having a discernible lag, but the strength of index extension was reduced to 49% of that of the normal finger. There was no evidence of functional loss. Extensor indicis proprius transfer for rupture of the extensor pollicis longus tendon is a simple and reliable procedure with few complications. It gives satisfactory long-term extension of the thumb.

Synovial chondromatosis in the distal interphalangeal joint.

A case of synovial chondromatosis of the distal interphalangeal joint of the long finger with an 8-year follow-up is presented. The lesion recurred 4 years after simple synovectomy, requiring a second operation with arthrodesis.

De Quervain's disease: surgical or nonsurgical treatment.

Ninety-one wrists in 82 consecutive patients with Quervain's disease were treated by the one surgeon between 1978 and 1987. The treatment of 79 wrists in 71 patients who had received their entire treatment from this surgeon is analyzed. Uniformity of injection technique is thus ensured. Initial treatment in 63 wrists was an injection of steroids and local anesthetic into the tendon sheath, which gave complete relief in 45 cases. Seven wrists received two injections before the pain abated. Only 11 of the 63 injected wrists had an operation. In 10 of these the extensor pollicis brevis tendon was in a separate compartment. It is concluded that injection of steroids is the preferred initial treatment in de Quervain's disease, giving complete and lasting relief in 80% of cases. If injection fails, it appears likely that the extensor pollicis brevis tendon lies in a separate compartment.

Three rare causes of extensor tendon rupture.

Three unusual cases of rupture of finger extensor tendons by attrition are reported. In one instance it was associated with long-standing nonunion of a scaphoid fracture, with a posttraumatic dorsal subluxation of the lower end of the ulna in another, and with a Madelung's deformity in the third. Extensor tendon rupture has not been previously recorded in the English-language literature after the first two conditions.

Carpal tunnel syndrome caused by a simple ganglion.

The compression of peripheral nerves by simple ganglia is a well recognised and documented clinical entity. It has been reported where ganglia have been associated with the ankle, knee and elbow joints (D.M. Brooks, 1952). It is probably best known in compression of the deep branch of the ulnar nerve in the wrist, first described by Seddon (Seddon H. J. 1952). Median nerve compression at the wrist, however, that causes a carpal tunnel syndrome would appear to be well recognized but poorly documented. Brooks (1952) described a case and until now, no others have been recorded in the literature. This case report describes such median nerve involvement with some interesting features.

Spontaneous recurrent ulnar dislocation of the long extensor tendons of the fingers.

Ulnar dislocation of the long extensor tendons of one or more fingers occurred in five elderly women. There was no history of trauma or any of the stigmata of rheumatoid arthritis. In all fingers there was loss of active extension in the metacarpophalangeal joints following flexion. It is postulated that this is a definite clinical entity occurring in the elderly associated with excessive joint laxity.

Bilateral ulnar "thumbs".

Congenital fusion of the carpal bones is fairly common and may be associated with other congenital deformities in the hand. This report deals with an unusual congenital anomaly of the little fingers associated with fusion of the triquetrum and lunate. Both little fingers were adducted and rotated giving crude resemblance to thumbs on the ulnar borders of the hands. The deformity was easily corrected by osteotomy through the base of the fifth metacarpals.

Bennett's fracture.

A new method of conservative treatment of Bennett's fracture is presented, the thumb being immobilised in moderate adduction rather than radial abduction. Anatomical dissections are outlined to demonstrate the rationale of this procedure.

Intramedullary nailing in the treatment of open fractures of the tibia and fibula.

Intramedullary nailing of thirty acute displaced open fractures of the tibia and fibula resulted in union with only one superficial infection. The low incidence of sepsis is attributed to the use of the curved malleable Hodgkinson tibial nail which requires no reaming, renders the operation less difficult and traumatic, and interferes minimally with bone vascularity. Fibular nailing was an effective means of stabilizing nine of the twelve fractures close to the ankle joint.