Circadian rhythm of plasma melatonin in endogenous depression

1. The circadian rhythm of plasma melatonin was investigated in normal men 18–30 years (N=5), normal men 50–70 years (N=5) and in six patients with endogenous depression.

2. The environmental photoperiod was 11 hours.

3. The subjects and patients were indoors with lights on from 07:00 until 23:00 hours.

4. Blood samples were obtained every 4 hours over a 24 hour period, with additional sampling at 22:00 and 02:00 hours.

5. Plasma melatonin was estimated by radioimmunoassay compared to both groups of controls.

6. In the depressed patients, the levels of melatonin were low throughout the 24 hour period.

7. The depressives had a delayed onset of the dark phase of the rhythm.

8. The patients also showed peak melatonin levels occurring earlier than in the controls.

9. Circadian rhythm of melatonin and therefore of its pacemaker may be altered in endogenous depression.     

Ellis—van creveld syndrome

Eleven cases of chondroetodermal dysplasia (Ellis-Van Creveld syndrome) occurring in three pairs of siblings and five isolated cases are described and literature reviewed.     

Chromatin condensation in the aging housefly

Computer analysis of digitized images of Feulgen-stained optic lobe and Malpighian tubule nuclei from the adult male housefly has shown significant age-related changes in several image features. These features relate to the amount and spatial distribution of a high and medium density chromatin component (HDC, MDC). Total DNA content in both the brain and tubule nuclei did not change with age.The amount of HDC nearly doubles by day 3 (post-eclosion) in the brain, while the amount in the tubules increases nearly four-fold by day 8. This condensation event is accompanied by a seven-to-eight-fold increase in the symmetry of the HDC distribution pattern. The number of MDC clusters in the tubule shows a five-fold decrease, while the number of MDC clusters in the brain remains unchanged.The condensation pattern in the brain nuclei changed more rapidly than it did in the tubule nuclei. The changes in the brain nuclei were found to occur between day 1 and day 4, while the tubule nuclei showed significant changes between day 1 and day 8. The significance of this difference is discussed with respect to Hypothalamic theories on the aging process in animals.     

The potent bone-resorbing mediator of Actinobacillus actinomycetemcomitans is homologous to the molecular chaperone GroEL.

Actinobacillus actinomycetemcomitans is a Gram-negative bacterium implicated in the pathology of localized juvenile periodontitis, a condition involving rapid destruction of alveolar bone. We have established that gentle extraction of this bacterium in saline releases a proteinaceous fraction (which we have termed surface-associated material [SAM] which has potent osteolytic activity in the murine calvarial bone resorption assay. Fractionation of the SAM has now revealed that activity is associated with a 62-kD protein. This bone-resorbing activity can be blocked by a monoclonal antibody (raised to the whole bacterium) that is claimed to recognize a protein homologous to the Escherichia coli molecular chaperone GroEL. Purification of this bone-resorbing protein to homogeneity has been achieved by a combination of anion exchange, gel filtration, and ATP-affinity chromatography and the NH2-terminal sequence shows > 95% homology to E. coli GroEL. This GroEL homologue is found in the SAM of A. actinomycetemcomitans but is not found in the osteolytically active SAM from other Gram-negative or Gram-positive bacteria. The GroEL protein from E. coli, but not from Mycobacterium tuberculosis and Mycobacterium leprae, also showed activity in the bone resorption assay. We believe this to be the first observation that a molecular chaperone has the capacity to stimulate the breakdown of connective tissue.     

Growth of Aeromonas spp. on Butzler Campylobacter selective agar and evaluation of the agar for the primary isolation of Aeromonas spp. from clinical specimens

The fortuitous finding that Aeromonas spp. grew well on Butzler Campylobacter selective medium (BCSA) in a microaerobic atmosphere at 42 degrees C prompted us to evaluate the performance of BCSA for selective isolation of aeromonads in comparison with ampicillin (30 micrograms/ml) sheep blood agar (ASBA30). Overall recovery rates of aeromonads from 563 stool samples from patients with acute diarrhea were higher on ASBA30 (70.4%) than on BCSA (56.3%); however, 21 (29.5%) grew only on BCSA. The three human-associated Aeromonas spp. could be recovered on BCSA and ASBA30. We recommend the use of BCSA to laboratories reluctant to include a specific selective medium for aeromonads.