Following a 7-day baseline period, five male hooded rats were injected daily with a constant dose (20 mg/kg) of morphine sulfate. Immediately following the injections they were taken to a sound-attenuated room and exposed to a 5,000 cps tone for 90 min. On certain predetermined days of the morphine treatment, rectal temperatures were measured before each injection and 30 min following the onset of the tone. Also, after the 11th, 19th, and 57th morphine-tone pairing, the rectal temperatures were measured before and after a saline injection which was paired with tone. On these days tone presentations by themselves were sufficient to cause a reliable increase in rectal temperature resembling that seen following an injection of morphine. When tone presentations were continued, without further pairng with morphine, the hyperthermic response to the tone was gradually extinguished. However, a significant increase in rectal temperature in response to the tone was again observed following a second set of five morphine-tone pairings.

Serum and tear IgA, IgG and IgM levels were studied in patients with bacterial, fungal and viral corneal ulcers. In patients with viral corneal ulcers serum IgA and IgG levels were found to be significantly raised, while IgM concentration remained unaltered. In bacterial and mycotic ulcerations, serum IgA, IgG and IgM levels remained unaltered. All three immunoglobulins were found to be raised in tears of patients with viral corneal ulcers, while only IgA levels were found to be increased in bacterial and mycotic ulcerations.

The past two decades have witnessed new facets in vitamin D metabolism. Free vitamin D3 till now considered to be limited to animal sources, has been shown to occur in plants. Further, the extrarenal synthesis of active vitamin D3 or calcitriol has been documented in physiological as well as in certain pathological conditions. At the cellular level, calcitriol acts through a dual mechanism.The genomic pathway involves the vitamin D receptor (VDR) which is of ubiquitous distribution and linked with various diseases. Besides, a nongenomic VDR -independent pathway also exists. The biological effects of calcitriol can no longer be dismissed by merely referring to calcium/bone homeostasis. It enhances the perinatal growth and suppresses the abnormal growth, as well. The effects on the endocrine, immune, cardiovascular, reproductive and nervous systems have also been characterized. It is compelling to believe that calcitriol and/or its analogues will find extensive applications at least in the treatment of osteoporosis, perinatal growth retardation, neoplasia, psoriasis, insulin resistance and transplantation.