Reciprocal behaviour associated with altered homeostasis and photosensitivity of Drosophila clock mutants

The circadian oscillators of genetically short-period and long-period Drosophila exhibit reciprocal behaviour in four distinct ways: (1) with respect to the dependence of period on temperature, (2) in the change of period during constant darkness after ten days of constant light, (3) in the change of period during the second ten days of darkness as compared with the period during the first ten days, and (4) in the period change resulting from exposure to low-intensity constant light. The homeostatic control of the dependence of period length on temperature is impaired in the mutants as compared with wild-type files. The normal Drosophila pacemaker may comprise two mutually coupled oscillators, whereas the mutants may represent a reduction in activity of one or the other constituent oscillator.     

Selective surgery for peptic ulcer: a review

Peptic ulcer patients do not fall into one secretory pattern and methods are available by which the secretory pattern may be assessed. Provided this assessment is accurate and the operation appropriate to the requirements of the individual patient is carried out, the side-effects are not severe.

The mortality from gastric surgery need not be above 1% and even when resection is involved the technical hazards of the operation are rarely the cause of death in experienced hands.

Further improvement in immediate and long-term results and protection against recurrence may be expected as the principles of selection become better understood and surgical procedures adequate to each requirement become standardized.

     

Rapid prenatal diagnosis of beta thalassemia using DNA amplification and nonradioactive probes

We used in vitro DNA amplification by the polymerase chain reaction and nonradioactive probes for prenatal diagnosis of beta thalassemia in Chinese from the Guangdong province. Exact molecular diagnoses were made in all 20 fetuses studied over a 6-month period. We conclude that this method of prenatal diagnosis for beta thalassemia is a viable approach in many parts of the world where this disease is common.