A glucose-sensing neuron pair regulates insulin and glucagon in Drosophila

Although glucose-sensing neurons were identified more than 50 years ago, the physiological role of glucose sensing in metazoans remains unclear. Here we identify a pair of glucose-sensing neurons with bifurcated axons in the brain of Drosophila. One axon branch projects to insulin-producing cells to trigger the release of Drosophila insulin-like peptide 2 (dilp2) and the other extends to adipokinetic hormone (AKH)-producing cells to inhibit secretion of AKH, the fly analogue of glucagon. These axonal branches undergo synaptic remodelling in response to changes in their internal energy status. Silencing of these glucose-sensing neurons largely disabled the response of insulin-producing cells to glucose and dilp2 secretion, disinhibited AKH secretion in corpora cardiaca and caused hyperglycaemia, a hallmark feature of diabetes mellitus. We propose that these glucose-sensing neurons maintain glucose homeostasis by promoting the secretion of dilp2 and suppressing the release of AKH when haemolymph glucose levels are high.

Osteosarcoma in New Zealand 1981-7: an overview

AIMS

To examine the incidence, and results of treatment of osteosarcoma in New Zealand between 1981 and 1987.

METHOD

Data was obtained from the Cancer Registry for all patients registered with osteosarcoma between 1981 and 1987.

RESULTS

There were 104 patients in the study group. There was a peak incidence in the second decade with a second smaller peak in the seventh and eight decades. The overall 5 year survival rate was 29%. For the group aged under 30 years there was a 44% 5 year survival rate. Those aged over 60 years had a 3.2% 5 year survival. Survival rates were better when treated with surgery and chemotherapy and where the tumour was of the appendicular skeleton.

CONCLUSION

This is a mixed group of patients. The 5 year survival rates appear to be at the lower end of the spectrum of the results reported for similar groups in other countries.

Dislocation of posteriorly stabilized total knee arthroplasties

Two cases of dislocation of an Insall-Burnstein II knee are reported. They occurred when a rotational force was applied to the loaded knee positioned in extreme flexion. Both dislocations were reduced closed and were found to be stable in the reduced position. The patients did well, and revision surgery was not required. No case of dislocation of this particular posterior stabilized total knee system has been reported previously.

The relationship between proximal femoral anatomy and osteoarthrosis of the hip

Proximal femoral anatomy in the anteroposterior plane was assessed by analysis of roentgenograms and the relationship between the anatomy and the pattern of osteoarthrosis of the hip was explored. The neck-shaft angle, the height of the femoral head, and the offset of the femoral head were analyzed and the type of osteoarthrosis classified according to Cameron and McNab. There was a significantly greater neck-shaft angle and a greater head height in the upward and outward migratory group. Patients being treated with total hip arthroplasty who exhibit certain types of proximal femoral anatomy might be expected to have increased acetabular loading and thus greater acetabular and femoral head wear. These data may have significance in the design of femoral components and the choice of implants in patients being treated with hip arthroplasty.

Displacement of subcapital fractures during internal fixation: a real problem?

The potential for femoral head rotation occurring during insertion of a compression hip screw has been investigated. Rotation to up to 30 degrees has been demonstrated, and was not visible on an image intensifier. The insertion of a guide-wire parallel to a hip screw does not control rotation adequately. Small threaded pins do not cause femoral head rotation.

Fractures of the lateral process of the talus

This study is a retrospective review of nine patients who sustained isolated fractures of the lateral process of the talus. The majority were caused by inversion or a combination of inversion and dorsiflexion of the foot. Following a review of the literature and anatomical dissections the authors recommend a classification based on anterior-posterior tomography of the talus, into intra- and extra-articular fractures.

Fractures of the proximal humerus in adults

Fractures of the proximal humerus are a common upper-extremity injury, particularly in the elderly. The literature suggests that the results of treatment of displaced fractures are generally unsatisfactory. Since Neer's articles in 1970 we found little reported in the literature on these fractures. We conclude from our review of 90 fractures that the results of treatment of displaced fractures continue to be unsatisfactory, and we believe that displaced proximal humeral fractures, along with femoral neck fractures, should be classified as unsolved fractures.