Presence of Penaeus monodon densovirus in the ovary of chronically infected P. monodon subadults.

Shrimp infected with Penaeus monodon densovirus (PmoDNV) usually display no specific gross signs, but heavy infections can kill postlarvae and retard juvenile growth. In the present study, samples of hepatopancreas, feces, gonads and hemolymph were isolated from male and female P. monodon subadults chronically infected by PmoDNV. Each sample of hepatopancreas and gonad was divided into 2 parts: one for PmoDNV detection by polymerase chain reaction (PCR), and the other for routine histology and immunohistochemistry. The frequency of positive findings via PCR assays was 92% in the hepatopancreas, 57% in feces, 50% in ovary, 35% in hemolymph and 0% in the testis. Using the densitometric value (DV) of the specific band for PmoDNV relative to that of the ß-actin gene as an index of the viral load in the samples, no significant differences were observed among sample types and sexes. Hematoxylin-eosin staining of infected hepatopancreas revealed typical PmoDNV inclusions in the nuclei of infected cells. The ovaries with high DV (>1) contained various types of inclusions along the row of the follicular cells or possibly in the connective tissue cells surrounding the oocytes. Using immunohistochemistry with specific probes to detect PmoDNV proteins, a positive reaction was observed in viral inclusions found in infected hepatopancreas and in ovaries with high DV, specifically in the ovarian capsule, hemolymph, oocytes and nuclear inclusions. These results suggest that the localization of PmoDNV in P. monodon is not confined to the hepatopancreas, but rather that the virus can also occur in the ovary; hence, trans-ovarian, vertical transmission of the virus is highly possible.

A randomized, open-label comparison of venlafaxine and fluoxetine in depressed outpatients.

In this randomized, open-label, 8-week comparative study, the efficacy and safety of venlafaxine and fluoxetine were assessed in outpatients with major depression. One hundred forty-five patients were assigned to receive venlafaxine 37.5 mg twice daily or fluoxetine 20 mg once daily. On day 15, if clinically indicated to improve patient response, the dosage could be increased at the investigator's discretion to venlafaxine 75 mg twice daily or fluoxetine 40 mg once daily. One hundred forty-five patients were evaluated for safety and 110, for efficacy. The mean age was 37 years, and 70% of the patients were female. In both treatment groups, mean scores on the Hamilton Depression Rating Scale decreased significantly between baseline (27.8, venlafaxine; 29.2, fluoxetine) and the end of the study (8.7, venlafaxine; 8.2, fluoxetine). Similarly, mean scores on the Montgomery-Asberg Depression Rating Scale decreased significantly between baseline (31.4, venlafaxine; 31.6, fluoxetine) and the end of the study (8.3, venlafaxine; 7.6, fluoxetine). In venlafaxine patients, the most common adverse events were nausea (44.3%), headache (40.0%), insomnia (31.4%), dizziness (30.0%), and dry mouth (22.9%); in fluoxetine patients, they were headache (32.0%), nausea (28.0%), insomnia (24.0%), anxiety (21.3%), sleepiness (20.0%), and generalized tremor (20.0%). The results of this study indicate that venlafaxine is effective and well tolerated for the treatment of major depression at doses of 37.5 or 75 mg twice daily and not significantly different from fluoxetine 20 or 40 mg once daily.