New and cost effective cell-based assay for Dialyzed Leukocyte Extract (DLE)-induced Jurkat cells proliferation under azathioprine treatment

The human Dialyzed Leukocyte Extract (DLE) is a heterogeneous mix of oligopeptides of <10kDa, extracted from leukocytes of healthy donors. There is significant clinical evidence of improvement using DLE during treatment of allergies, cancer,immunodeficiencies, and in mycotic and viral infections. Nevertheless, the DLE exact nature and mechanism of action have been elusive for more than 50 years. DLE biological activity testing is necessary in DLE production and quality control. Both in vitro and in vivo assays exist: E-rosette test, induction of delayed type hypersensitivity in mice, leukocyte migration and IFN-γ secretion. The animal-origin materials and in vivo assays convey a considerable logistic, ethic and economic burden, meanwhile the available in vitro assays have been reported with limited reproducibility and sometimes contradictory results. Here we are reporting a new DLE biological activity cell-based assay. The A20 and Jurkat cell lines were treated with (+Aza) or without (-Aza) azathioprine, DLE (+DLE) or both (+Aza/+DLE). After 72h, the cell proliferation was analyzed by the MTT or BrdU incorporation assays. In +Aza/+DLE treated cells, we observed a significant higher proliferation, when compared with +Aza/-DLE. In the absence of Aza, cells did not present any proliferation difference between -DLE or +DLE treatments. Both assays, MTT and BrdU showed similar results, being the MTT test more cost effective and we select it for validation as DLE biological assay using Jurkat cells only. We tested three different lyophilized DLE batches and we found consistent results with acceptable assay reproducibility and linearity. The DLE capacity for rescuing Jurkat cell proliferation during +Aza treatment was consistent using different liquid and lyophilized DLE batches, presenting also consistent chromatographic profiles. Finally, DLE treatment in Jurkat cells did not result into significant IL-2 of IFN-γ secretion, and known lymphocyte proliferative drugs failed to rescue Jurkat cells viability in presence of +Aza, as +DLE treatment did in our MTT assay. In conclusion, our new cell-based MTT assay has excellent DLE biological activity consistency, robustness and is cost effective, presenting important advantages over previous DLE activity in vitro and in vivo assays.

An early function of the adenoviral E1B 55 kDa protein is required for the nuclear relocalization of the cellular p53 protein in adenovirus-infected normal human cells

It is well established that the human subgroup C adenovirus type 5 (Ad5) E1B 55 kDa protein can regulate the activity and concentration of the cellular tumor suppressor, p53. However, the contribution(s) of these functions of the E1B protein to viral reproduction remains unclear. To investigate this issue, we examined properties of p53 in normal human cells infected by E1B mutant viruses that display defective entry into the late phase or viral late mRNA export. The steady-state concentrations of p53 were significantly higher in cells infected by the E1B 55 kDa null mutant Hr6 or three mutants carrying small insertions in the E1B 55 kDa protein coding sequence than in Ad5-infected cells. Nevertheless, none of the mutants induced apoptosis in infected cells. Rather, the localization of p53 to E1B containing nuclear sites observed during infection by Ad5 was prevented by mutations that impair interaction of the E1B protein with p53 and/or with the E4 Orf6 protein. These results indicate that the E1B protein fulfills an early function that correlates efficient entry into the late phase with the localization of E1B and p53 in the nucleus of Ad5-infected normal human cells.

Nuclear estrogen and progesterone receptors in the oviduct of heifers under natural and superovulated estrous cycles

Oviducts from 22 crossbred heifers were examined for the presence of nuclear estrogen (ERalpha) and progesterone (PR) receptors at different phases (estrus, metaestrus and diestrus) of naturally occurring estrous cycles and estrous cycles during which superovulation was induced. Receptors were detected by immunohistochemistry in the epithelial cells, connective tissue and muscular layer of oviductal infundibulum, ampulla, ampullary/isthmic transition and isthmus. Epithelial ERalpha was found along the entire oviduct regardless of the cycle phase and of the circulating concentrations of 17beta-estradiol (E(2)) and progesterone (P(4)). Epithelial PR was found mainly at the ampullary-isthmic transition and isthmus and more intensely at the estrus phase but their amount was not correlated with P(4) concentrations. ERalpha in the connective tissue was more abundant at the infundibulum and ampulla, regardless of the phase of the estrous cycle and of E(2) and P(4) circulating concentrations. PR in the connective tissue was found mostly at the ampulla, regardless of the estrous cycle phase but no correlations were found between amount and P(4) concentrations. ERalpha staining intensity in the muscular layer was similar at all phases of the estrous cycle and at all anatomical segments of the oviducts. However, PR staining was more intense at the isthmus during the metaestrus phase and it was negatively correlated with P(4) concentrations. In general, data from the present research suggest that P(4) exerts an inhibitory role upon ERalpha and PR. Also, no differences were found between animals subjected or not to superovulation.

Plasma and testicular testosterone levels, volume density and number of Leydig cells and spermatogenic efficiency of rabbits

Plasma and tissue testosterone concentrations were determined by radioimmunoassay in 12 eight-month-old sexually mature New Zealand White rabbits and evaluated for possible associations with spermatogenic efficiency as well as with volume density and number of Leydig cells. Testicular tissue was processed histologically and histometry was performed in order to quantify germ cells, Sertoli cells and Leydig cells. Spermatogenic efficiency, reported as the ratios among germ cells (spermatogonia, primary spermatocytes and round spermatids) and by the ratio of germ cells to Sertoli cells, was not associated with testosterone levels. However, Leydig cell parameters such as number of Leydig cells per gram of testis, total number of Leydig cells per testis and percent cell volume of Leydig cell nuclei were correlated significantly with testosterone levels. The statistically significant correlation (r = 0.82, P<0.05) observed between testosterone levels and the number of Leydig cells per gram of testis suggests that, in the rabbit, the latter parameter can serve as a criterion for monitoring testosterone levels in this species under normal conditions.

Duration of spermatogenesis and sperm transit time through the epididymis in the Piau boar

The Piau boar is a rustic breed of economical importance in Brazil. The duration of spermatogenesis and sperm transit through the epididymis in Piau boars was estimated using intratesticular injections of tritiated thymidine. Animals were sacrificed 1 h, 7 days, 14 days, 21 days, 34 days, and 36 days after injections. Each cycle of spermatogenesis in Piau boars lasts 9 +/- 0.2 days. At least 9 days are necessary for spermatozoa to traverse the entire epididymis. Considering that the total duration of spermatogenesis takes about 4.5 seminiferous epithelium cycles, spermatogenesis was estimated to take 40.6 days. The primary spermatocytes life span is 13.5 days, while spermiogenesis in Piau boars lasts 14.5 days. Staging in Piau boars was based on tubular morphology system. The relative stage frequencies in these boars, based on approximately 1200 seminiferous tubule cross-sections for each animal, were as follows: stage 1, 11.7 +/- 0.7%; stage 2, 14.3 +/- 0.3%; stage 3, 5.4 +/- 0.1%; stage 4, 12.1 +/- 0.6%; stage 5, 9.6 +/- 0.4%; stage 6, 17.2 +/- 0.4%; stage 7, 15.4 +/- 0.8%; and stage 8, 14.3 +/- 0.9%. The duration of spermatogenic events and the relative stage frequencies in Piau boars differ slightly from those observed in improved swine breeds.

Gonadal and extragonadal sperm reserves of the Brazilian Nelore zebu (Bos indicus)

Gonadal and extragonadal sperm reserves were estimated through hemocytometric method in six Nelore zebu bulls, aging 4-6 years, with normal spermatogenesis, and kept at sexual rest. Gonadal sperm reserve was estimated to be 47.8 +/- 5.8 X 10(6) sperm cells/g testis parenchyma and 9.8 +/- 1.7 X 10(9) sperm cells/testis. Using a time divisor of 4.94 days the daily sperm production was estimated to be 10.0 +/- 0.9 X 10(6) sperm cells/g testis parencyma/day and 2.0 +/- 0.3 X 10(9) sperm cells/testis/day. Epididymal sperm reserve amounted 11.9 +/- 1.6 X 10(9) spermatozoa/organ, distributed as follows: 35.3 +/- 3.6% in the head, 16.9 +/- 1.7% in the body and 47.7 +/- 3.7% in the tail.

Age-related changes in the seminal vesicles of a Brazilian (Nelore) zebu

Age changes in the structure of the seminal vesicles and in the rate of production of fructose and citric acid have been studied in a Brazilian (Nelore) zebu, from the fetal period to 36 months of age. At 3 and 6 months, the microscopic anatomy of the gland resembled that of the fetus; the tubules of the seminal vesicles had a reduced diameter and a low epithelial layer; only a few presented traces of secretion, and tissue contents of fructose and citric acid were accordingly low. At 12 months, the tubules were more ramified and had a larger diameter. In the 18-month-old animals the seminal vesicles presented substantial modifications; the tubules were large, with irregular lumina and surrounded by narrow stroma, the epithelial layer was higher than that of previous stages and its columnar cells had nuclei located basally. Tissue levels of fructose increased rapidly between 12 and 18 months. At 24 months, the seminal vesicles had reached the adult condition characterized by intense proliferation of tubules with irregular lumina and abundant secretory material. Numerous dark columnar cells were found in the epithelium. Seminal vesicles of Nelore zebus contain less fructose and citric acid than those of taurine bulls of comparable age.

Microscopic anatomy of the scrotum, testis with its excurrent duct system and spermatic cord of Didelphis azarae

The authors give a description of the microscopic anatomy of the scrotum, testis and its excurrent duct system and the structures of the spermatic cord. The scrotal skin of Didelphis azarae is hairy with the surface marked by shallow grooves and spotted with black pigmented areas. Clear cells and mitotic figures are frequently seen in the basal region. The sweat glands are tubular, apocrine, with alcian-blue- and PAS-positive secretion, presenting large myoepithelial cells. The tunica dartos is poorly developed. The tunica vaginalis is constituted by three layers, presenting patches of melanocytes in variable extensions. The tunica albuginea is composed preponderantly of collage and thin elastic fibers without muscle fibers. The interstitial tissue presents connective cells and a large number of Leydig cells. Mast cells were not observed. The tunica propria of the seminiferous tubuli is fibroelastic with two or three layers of elongated cells. The straight tubuli are divided into three different portions lined by epithelium with variable height. These tubuli at the mediastinum join each other to form a single duct near the cranial pole of the testis. The extratesticular segment of the efferent duct divides initially into two and then into three or four smaller flexuous ductuli to constitute the head of the epididymis. The spermatic cord shows a well-developed cremaster muscle. A collagenous fibrous band separates the muscle from the deferent duct and vessels. Mast cells are observed among the muscle fibers of the cremaster and the tunica adventitia of the blood vessels.

Blood supply to the testis of a Brazilian marsupial (Didelphis azarae) and its abdominotesticular temperature gradient

The testicular arteries of Didelphis azarae originate from the abdominal aorta either independently from each other or by way of a common trunk. Accessory testicular arteries may be found. At the spermatic cord they form a rete mirabile having 26.8 +/- 5.0 and 29.3 +/- 4.9 slender branches on the right and left sides, respectively. The arterial branches are intermingled with veins of similar caliber and number. Near the testis the branches of the rete reunite in a single vessel which then penetrates the parenchyma of the testis. Inside the testis the artery divides usually into two main branches that course toward the caudal pole. The rectal, scrotal and testicular temperatures were 32, 28.5 and 30.4 degrees C, respectively, appearing than an abdominotesticular gradient temperature exists in this animal. Whether this mechanism is thermoregulatory for the normal spermatogenesis cannot be inferred from the present work.