Enrichment and In Vitro Culture of Spermatogonial Stem Cells from Pre-Pubertal Monkey Testes

Spermatogonial stem cells (SSCs) are essential for spermatogenesis throughout the lifespan of the male. However, the rarity of SSCs has raised the need for an efficient selection method, but little is known about culture conditions that stimulate monkey SSC proliferation in vitro. In this study, we report the development of effective enrichment techniques and in vitro culturing of germ cells from pre-pubertal monkey testes. Testis cells were analyzed by fluorescence-activated cell sorting techniques and were transplanted into the testes of nude mice to characterize SSCs. Thy-1-positive cells showed a higher number of colonies than the unselected control after xenotransplantation. Extensive colonization of monkey cells in the mouse testes indicated the presence of highly enriched populations of SSCs in the Thy-1-positive sorted cells. Furthermore, monkey testis cells were enriched by differential plating using extracellular matrix, laminin, and gelatin, and then cultured under various conditions. Isolation of monkey testicular germ cells by differential plating increased germ cell purity by 2.7-fold, following the combinational isolation method using gelatin and laminin. These enriched germ cells actively proliferated under culture conditions involving StemPro medium supplemented with bFGF, GDNF, LIF, and EGF at 37 ℃. These results suggest that the enrichment and in vitro culture method proposed in the present study for harvesting a large number of functionally active monkey SSCs can be applied as the basis for efficient in vitro expansion of human SSCs.

Clinical Review of Laparoscopic Cholecystectomy

Since laparoscopic cholecystectomy(LC) was first introduced in early 1990 in Korea, LC is now widely used with an acknowledgement of the benefits of LC.The author retrospectively analyzed 120 patients who were treated by LC and 40 patients who were treated by open cholecystectomy(OC), at the Department of Surgery, Kwang Hye Hospital from Jan. 1992 to July 1995. For the statistical analysis of the variables, student's t-test and ANOVA F-test were used to assess the differences between two groups(p value = 0.05). The obtained results were as follows. 1. The mean age and sex ratio(M:F) between LC and OC group were 48.3-years-old and 1:1.45, 57.6-years-old and 1:3.4, respectively. 2. Associated diseases were observed in 62 patients (51.7%) of the LC group and 23 patients (57.5%) of the OC group. Peptic ulcer and DM were most frequent, respectively. 3. 20 patients (16.7%) had a previous abdominal operation, with appendectomy, the most frequent among them. 4. The operation times(p=0.05), hospitalization stay(p=0.0001), and postoperative hospitalization stay(p=0.0001) were significantly shorter in the LC group than in the OC group. 5. In the preoperative, intraoperative, and postoperative ABGA of the LC group, especially, intraoperative PCO2 was increased due to CO2 retension and metabolic acidosis was developed, intraoperatively. PaO2 was excessively increased due to hyperventilation to correct the metabolic acidosis, intraoperatively. Satistically, intraoperative pH (p=0.0001), PaO2 (p=0.0001), PCO2 (p=0.0001) except bicarbonate (p=0.1987) were significantly changed, compared with preoperative pH or postoperative pH. 6. Operative cholangiography(OPC) was proceeded in 17 patients(14.2%) and concurrent laparoscopic appendectomy was done in 7 patients (5.8%) of the LC group. 7. Postoperative complications were occurred in 19 patients (15.8%) of the LC group. 3 patients (2.5%) were explorated, the remainders were recovered by conservative treatment. 8. On pathologic findings, cholelithiasis and chronic cholecystitis with 105 patients (87.5%) were most frequent in the LC group. In the OC group, cholelithiasis and chronic cholelithiasis with 25 patients (62.5%) were also most frequent, GB empyema with 8 patients (20%), acute cholecystitis with 7 patients (17.5%). Conclusively, laparoscopic cholecystectomy can be safely applied with lower morbidity, shorter operation times, and shorter hospital stay in selected patients.