Isospora belli and Cryptosporidium sp. from a patient not suspected of having acquired immunodeficiency syndrome.

Several protozoa including Cryptosporidium sp. and Isospora belli were found in a stool specimen from a patient not suspected of having Acquired Immunodeficiency Syndrome (AIDS). As a result of the parasitologic findings, serologic tests were ordered that verified the diagnosis of AIDS. All stool specimens are routinely tested for presence of acid fast organisms with a modified acid fast technique.

Cost containment of formalin-preserved stool specimens for ova and parasites from outpatients.

Three individual formalinized stool specimens from each of 123 patients were pooled and examined for ova and parasites. Results obtained from the pooled specimens were compared with those obtained with the three individual specimens used to make the pooled specimens. Of 123 sets examined, 92 were negative and 31 were positive for ova and parasites. The pooled specimens were positive and all individual specimens were negative eight times, whereas the pooled specimens were negative and the individual specimens were positive twice. The data indicated that the pooled system is a useful and economical method of screening for ova and parasites.

Prevalence of enteric parasites in homosexual patients attending an outpatient clinic.

A total of 372 pooled stool specimens from 274 homosexual men with diarrhea were submitted for parasitologic examination over a 2.5-year period. Each two-vial pooled specimen set contained portions of stool from 3 consecutive days in Formalin and polyvinyl alcohol. Of the 274 patients, 133 (48.5%) harbored one or more intestinal protozoa, with 161 (43.3%) of the 372 specimens submitted being positive for one or more organisms. The parasites identified included Entamoeba histolytica (71 patients), Giardia lamblia (22 patients), Endolimax nana (106 patients), Entamoeba coli (39 patients), Entamoeba hartmanni (25 patients), Dientamoeba fragilis (3 patients), Iodamoeba bütschlii (2 patients), and Chilomastix mesnili (2 patients). Cryptosporidium sp. (2 patients) and Isospora belli (1 patient) were also detected. Results of this study support the experience of other workers regarding high rates of infection with intestinal parasites in the homosexual population and also indicate that symptomatic individuals belonging to this acquired immunodeficiency syndrome risk group be screened for both common and uncommon intestinal pathogens.

Clinical characteristics of seven cases of diarrhea associated with a novel acid-fast organism in the stool.

In the last 4 years, we have identified an acid-fast, autofluorescent organism in the stool of seven patients with diarrhea. The organism was identified as a cyanobacterium-like organism by the Centers for Disease Control (Atlanta) and as a coccidian by researchers in Peru and at the University of Arizona (Tucson). We present reports on the seven cases and a review of the literature. Three patients were known to be seropositive for the human immunodeficiency virus (HIV). All complained of watery diarrhea that had begun 3 days to 8 months before presentation. Colonoscopy in two patients showed a normal mucosal pattern; a biopsy for one of these patients showed chronic nonspecific inflammation of the colon. Examination of stool for ova and parasites revealed multiple oval and round nonrefractile organisms with well-defined walls that resembled large cryptosporidia; they measured 8-9 microns in diameter. These organisms did not stain by Giemsa or gram methods but were acid-fast by Kinyoun carbolfuchsin and Ziehl-Neelsen stains. The organisms fluoresced as blue under ultraviolet light. In the immunocompetent patients, diarrhea lasted an average of 19 days and resolved spontaneously. Diarrhea persisted in the HIV-seropositive patients. The clinical course and organism resembled those reported for travelers and HIV-seropositive patients. This organism may represent a newly identified cause of watery diarrhea in humans.

ATF-7, a novel bZIP protein, interacts with the PRL-1 protein-tyrosine phosphatase.

We have identified a novel basic leucine zipper (bZIP) protein, designated ATF-7, that physically interacts with the PRL-1 protein-tyrosine phosphatase (PTPase). PRL-1 is a predominantly nuclear, farnesylated PTPase that has been linked to the control of cellular growth and differentiation. This interaction was initially found using the yeast two-hybrid system. ATF-7 is most closely related to members of the ATF/CREB family of bZIP proteins, with highest homology to ATF-4. ATF-7 homodimers can bind specifically to CRE elements. ATF-7 is expressed in a number of different tissues and is expressed in association with differentiation in the Caco-2 cell model of intestinal differentiation. We have confirmed the PRL-1.ATF-7 interaction and mapped the regions of ATF-7 and PRL-1 important for interaction to ATF-7's bZIP region and PRL-1's phosphatase domain. Finally, we have determined that PRL-1 is able to dephosphorylate ATF-7 in vitro. Further insight into ATF-7's precise cellular roles, transcriptional function, and downstream targets are likely be of importance in understanding the mechanisms underlying the complex processes of maintenance, differentiation, and turnover of epithelial tissues.