The effects of dronabinol on appetite and weight were evaluated in 139 patients with AIDS-related anorexia and > or = 2.3 kg weight loss in a multi-institutional study. Patients were randomized to receive 2.5 mg dronabinol twice daily or placebo. Patients rated appetite, mood, and nausea by using a 100-mm visual analogue scale 3 days weekly. Efficacy was evaluable in 88 patients. Dronabinol was associated with increased appetite above baseline (38% vs 8% for placebo, P = 0.015), improvement in mood (10% vs -2%, P = 0.06), and decreased nausea (20% vs 7%; P = 0.05). Weight was stable in dronabinol patients, while placebo recipients had a mean loss of 0.4 kg (P = 0.14). Of the dronabinol patients, 22% gained > or = 2 kg, compared with 10.5% of placebo recipients (P = 0.11). Side effects were mostly mild to moderate in severity (euphoria, dizziness, thinking abnormalities); there was no difference in discontinued therapy between dronabinol (8.3%) and placebo (4.5%) recipients. Dronabinol was found to be safe and effective for anorexia associated with weight loss in patients with AIDS.

The effects of flow on the physiological ecology of Montustrea annuluris, an important framebuilding species of Caribbean coral reefs, were investigated in situ with a recirculating flow respirometry system deployed from an underwater habitat. For this species, primary production and respiration rates increase with increasing water motion. The slope of a nondimensional Sherwood (Sh)-Reynolds(Re) number plot indicates that forced convection increases dark respiration in a manner consistent with oxygen transfer through a turbulent boundary layer (Sh = 0.01Re'.30). A similar analysis for maximal photosynthetic rate yields a lower but significant slope (Sh = 0.7 1 Reo.63). A simple conceptual model of diffusional depletion in the boundary layer over the coral fits the data and accounts for the distribution of zooxanthellae. Calculations of phototrophic capacity for this species indicate that water motion can enhance the local productivity of the reef.

The colonial ascidian—algal symbiosis Didemnum molle Herdman occurs in large numbers (densities of >100 colonies/m2) on shallow patch reefs in the lagoon at Lizard Island, Australia. Shallow—water currents in the lagoon are driven unidirectionally by the southeast trade winds most of the year. The patch reefs are several hundred metres apart and are separated by sand flats. The largest populations of D. molle occur on the upstream ends of the patch reefs. D. molle larvae, followed underwater, dispersed invariably downstream in the direction of the water current at °1—2 m/min. Although larvae were capable of swimming for up to 2 h, they generally settled in 10—15 min when given a suitable substratum such as a dark surface. Larvae experimentally denied a suitable substratum for 40 min settled rapidly when provided with a dark surface, suggesting that when larvae encounter a reef after drifting over sand flats, they probably settle immediately. A qualitative model of larval dispersal was developed to predict the settlement pattern of D. molle in the lagoon at Lizard Island. Three predictions of the model were tested by measuring larval recruitment upstream and downstream of an experimental patch reef for 1 wk before, then 1 wk after denuding the reef of all reproductive D. molle colonies. The results agree with the model, indicating that larval recruitment of D. molle in the lizard Island lagoon is a highly predictable process. The settlement pattern that results from the dispersal model describes the upstream distribution of adult D. molle colonies on patch reefs in the Lizard Island lagoon.

We studied the effects of long-term (12 months) dronabinol in 94 late-stage acquired immunodeficiency syndrome (AIDS) patients (mean CD4 count of 45/mm3) who previously participated in a 6-week study (placebo versus dronabinol). All patients received dronabinol orally-2.5 mg twice daily (90%) or 2.5 mg once daily (10%). Appetite was measured using a visual analogue scale for hunger (VASH). Dronabinol was associated with consistent improvement in mean appetite. Patients previously treated with dronabinol continued to show improvement in VASH (percent change from baseline of 6-week trial: 48.6-76.1% at each month), whereas those previously treated with placebo exhibited substantial improvement in mean appetite, particularly during the initial 4 months of treatment (48.5-69.9%). Thereafter, dronabinol was associated with a VASH change at least twice baseline. Patients tended toward stable body weight for at least 7 months. Adverse events were primarily related to known central nervous system effects of dronabinol. These data support long-term, safe use of dronabinol for anorexia associated with weight loss in patients with AIDS.

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