Insulin resistance in the aged: a quantitative evaluation of in vivo insulin sensitivity and in vitro glucose transport

It has recently been made clear that reduced sensitivity to exogenous insulin can be demonstrated in the course of aging. This phenomenon has been further investigated with the aid of sophisticated techniques, such as the euglycemic clamp, which, when coupled with the measurement of hepatic glucose production, showed that "impaired tissue sensitivity to insulin is the primary factor responsible for the decrease of glucose tolerance in advancing age." Nevertheless, this study did not establish whether such impairment reflects reduced sensitivity (receptor deficiency) or reduced response (postreceptor or receptor plus postreceptor defect), as shown in other diseases. Evidence in favor of the view that receptor deficiency is responsible can be seen in our observation of an approximately 50% reduction in receptors in a study of insulin binding on isolated human fat cells. Two aspects of this question appeared to require further investigation: tissue sensitivity to receptor-saturating insulin concentration (euglycemic clamp at about 1000 microU/mL plasma insulin), and the glucose transport system coupled to the receptor. A decrease in receptors alone should shift the insulin sensitivity curve to the right, both in vivo (euglycemic clamp) and in vitro (glucose transport), with no reduction of the maximum effect. A solution to this question is proposed in the light of a study conducted on young volunteers and subjects over 65 years old.     

Treatment of localized prostate cancer using a combination of high dose rate Iridium‐192 brachytherapy and external beam irradiation: Initial Australian experience

Combination high dose rate brachytherapy (HDRB) and external beam radiation therapy is technically and clinically feasible as definitive treatment for localized prostate cancer. We report the first large Australian experience using this technique of radiation dose escalation in 82 patients with intermediate‐ and high‐risk disease. With a median follow up of 3 years (156 weeks), complications were low and overall prostate‐specific antigen progression‐free survival was 91% using the American Society for Therapeutic Radiology and Oncology consensus definition. The delivery of hypofractionated radiation through the HDRB component shortens overall treatment time and is both biologically and logistically advantageous. As a radiation boost strategy, HDRB is easy to learn and could be introduced into most facilities with brachytherapy capability.     

Screening for complement deficiency in bacterial meningitis

Seventy-seven children with bacterial meningitis were screened for complement deficiency. Both the classical and the alternate pathways were normal in 75 patients. Transiently reduced total haemolytic activity of the classical pathway was documented in a boy with meningococcal meningitis. Total haemolytic activity of both the classical and the alternate pathways were reduced in another patient with pneumococcal meningitis: individual complement components determination indicated predominant activation of the alternate pathway.     

Tunneling Schmorl’s nodes in an elderly woman treated for acute lymphoblastic leukemia

We present a 70-year-old woman with pre-B acute lymphoblastic leukemia in whom serial imaging studies showed the development of multiple vertebral collapse, and communicating superior and inferior Schmorl’s nodes creating a longitudinal channel (”tunneling” Schmorl’s nodes) through the anterior aspect of T12 to L3 vertebral bodies of her osteoporotic thoracolumbar spine. This was observed after achieving complete remission of the disease and during maintenance therapy. The finding is felt to be secondary to iatrogenic exacerbation of osteoporosis. Received: 26 May 2000 Revision requested: 23 June 2000 Revision received: 10 July 2000 Accepted: 13 July 2000     

The epidemiology of preterm labour—why have advances not equated to reduced incidence?

The major burden of preterm birth is in the developing world, where most of the increasing death and morbidity is secondary to infectious diseases such as malaria, HIV, tuberculosis, bacterial vaginosis and intestinal parasites. In some developing countries, the growth of medical care has outstripped the growth of preventive public health, with an associated increase in iatrogenic preterm births. In developed countries, more than one-third of preterm births are medically indicated because of conditions such as fulminating pre-eclampsia or severe intrauterine growth restriction. Neither of these conditions is currently preventable. One in five preterm births is associated with multiple pregnancy, and these have been greatly increased by assisted reproduction techniques. The use of tocolytics has proved disappointing perhaps because inflammation rather than spontaneous uterine activity is increasingly recognised as the final common pathway. Inappropriate antibiotics used late in pregnancy are ineffective and may have adverse effects. Currently, the most promising interventions are public health related and include reducing the transmission of communicable diseases, improvements in the management of diabetes and reduction in harmful behaviours such as smoking and drug abuse.