Empty sella syndrome in childhood

The empty sella syndrome is common in middle-aged women, usually presenting with headache, and only occasionally associated with endocrine or visual abnormalities. It is rare in childhood. Childhood cases tend to present either with endocrine disturbances, visual symptoms, or with craniofacial syndromes. We present three cases of complete empty sella with childhood onset, each discovered unexpectedly during evaluation of endocrine or visual dysfunction.     

False negative hepatitis B surface antigen detection in dialysis patients due to excess surface antigen: postzone phenomenon.

Renal dialysis patients are well known to have a high incidence of hepatitis B carrier state. In studying a group of 63 long-term dialysis patients, 10 were found to be positive for hepatitis B surface antigen by radioimmunoassay (RIA). Surprisingly, however, only three of these RIA positive patients were positive by counter immunoelectrophoresis (CIEP). The discrepancy could not be accounted for by the difference in sensitivity of the two methods. The cause for the negative reactions by CIEP in seven patients was found to be the marked excess surface antigen in these sera which produced false negative results by the postzone phenomenon. After dilution all seven sera were positive by CIEP, requiring a dilution up to 1/20 to produce a positive result. Also, all seven sera were positive by the less sensitive Ouchterlony double diffusion.     

Effect of injury on shivering thermogenesis in the rat

1. Shivering in response to changes in ambient or core temperature has been measured in control rats and rats injured by bilateral hind-limb ischaemia, both with and without fur.2. Removal of the fur increased the threshold ambient temperature for the onset of shivering.3. This threshold was lower than in uninjured controls during the latter half of a 4 hr period of bilateral hind-limb ischaemia in rats with or without fur.4. The threshold was also lower than in uninjured controls after the period of bilateral hind-limb ischaemia but was not significantly different from that during the period of ischaemia.5. The alterations in threshold were not accompanied by any significant changes in the slope of the regression line relating intensity of shivering and ambient temperature.6. When the core temperature fell after limb ischaemia to levels which provoked shivering in uninjured controls, no shivering was seen in the injured rats.7. These results are interpreted as further evidence for the lowering of the ;set-point' for thermogenesis after injury in the rat and are discussed in relation to the changes in body temperature after injury in that species.     

Effect of transport time, temperature, and concentration on the survival of group B streptococci in amies transport medium

The impact of transport time and temperature on survival of group B streptococci (GBS) in Amies transport medium was evaluated. Viability of 10 or more CFU of GBS was maintained for 4 days at 24 or 3 degrees C. However, there was a significant decrease in viability for GBS held at 30 degrees C for 4 days.     

Polyomavirus Models of Brain Infection and the Pathogenesis of Multiple Sclerosis

Multiple sclerosis (MS) is generally considered to be an autoimmune disorder with myelin as the target and with several unidentified viruses playing ancillary roles, possibly through molecular mimicry. Although this paradigm has led to important progress on potential mechanisms of myelin loss, neither a target antigen in myelin nor a triggering mechanism has yet been identified, leaving the etiology of MS still unknown. Animal models of viral demyelination and studies showing that JC virus (JCV), the polyomavirus which causes progressive multifocal leukoencephalopathy (PML), may be latent in some normal human brains suggest another possibility. A host immune response targeting proteins expressed at low levels from viral DNA latent in the central nervous system (CNS) might underlie a focal demyelinating disease such as MS. A shift from autoimmunity to a latent-virus model is not a trivial substitution of target antigens. This shift would expand the search for a definitive laboratory test for MS and could lead to improved therapeutic and preventive approaches.