Vasal anastomoses in dogs using contact neodymium:yttrium aluminum garnet (Nd:YAG) laser

The purpose of this study is to evaluate the contact Nd:YAG laser system for vasal anastomosis in the animal model. Eighteen mongrel dogs were used. In this study, two major groups--control and laser--were defined. In the control group, vas anastomoses were performed with conventional microsurgical technique in six dogs. In the laser group, we performed contact laser assisted vas anastomosis (CLAVA) in 12 dogs by means of a contact Nd:YAG laser with synthetic sapphire probe (ERP4), emitted 2.0 sec pulse duration of minimum 1 watt to maximum 10 watts power. The time needed for completion of the vasal anastomosis in CLAVA group was 2-3 min; in the control group, approximately 25 min. The patency rate did not differ in these two groups; however, microscopic sperm granuloma formation was 16.7% (2/12) in the control group but 0% (0/12) in the CLAVA group. In conclusion, CLAVA is a fast and simple technique for vasal anastomosis and there were no significant complications, sperm granuloma, or even significant swelling or hematoma in any animal in this experiment.

Extended temporal gradient for the retrograde and anterograde amnesia produced by ibotenate entorhinal cortex lesions in mice

Effects of ibotenic entorhinal cortex (EC) lesions on both retrograde and anterograde amnesia in mice were assessed using two-choice discrimination tasks learned at different intervals before surgery in two eight-arm radial mazes. The results indicated that EC-lesioned mice were severely impaired in postoperative retention of discrimination problems learned 3 d or 2 weeks prior to surgery, but showed no deficit on problems learned between 4, and up to 6 weeks before surgery, as compared to sham-operated controls. When trained on a novel two-choice discrimination problem (not acquired preoperatively), experimental subjects demonstrated quite normal rates of acquisition, but were impaired in learning its reversal. Furthermore, they exhibited a faster rate of forgetting (anterograde amnesia) relative to controls over a 2-week retention interval. These results indicate that approximately 4 weeks is required before memory for a two-choice spatial discrimination problem no longer depends on the integrity of the entorhinal cortex, and suggests that, beyond this time, an EC-independent memory storage system is capable of supporting the retrieval of information. The data, together with complementary behavioral results, are discussed in the context of current theories of memory storage.

Adriamycin absorption after Nd:YAG laser coagulation compared to electrosurgical resection of the bladder wall

The toxicity of intravesical drugs used for the treatment of bladder cancer is increased by systemic absorption. Therefore, treatment is often delayed several weeks after transurethral resection until sufficient healing occurs. Since a neodymium:YAG laser causes tissue injury by thermal coagulation, we investigated differences in bladder permeability after laser treatment compared to TUR. Comparable 2.5 cm in diameter areas of tissue injury were created in the bladder of mongrel dogs either by Nd:YAG laser coagulation or transurethral electrocautery resection (TUR). Subsequently, 30 mg. of adriamycin were instilled intravesically. A control group consisted of animals receiving adriamycin alone. Blood was taken at 10, 30, 60, and 120 minutes after instillation and the serum concentration of adriamycin measured quantitatively by high performance liquid chromatography (HPLC) with fluorescence detection. The maximum serum ADM concentration during 120 minutes for the control group was 28.0 +/- 12.9 ng/ml compared to 38.9 +/- 4.8 for the laser group and 102.9 +/- 29.9 for TUR. The area under the curve was 35.1 +/- 10.2 ng x hours/ml for control, 43.5 +/- 3.9 for laser and 127.7 +/- 49.9 for TUR. Using a two-tailed Student's t test, the difference between the TUR and the laser group was significant (p less than 0.01). There was no difference between laser and control. These results suggest that laser treatment has minimal effect on the absorption of drugs from the bladder. The clinical practice of delaying intravesical therapy after TUR is verified but a similar policy may not be necessary after laser treatment.

Effects of photodynamic therapy in combination with intravesical drugs in a murine bladder tumor model

This study was designed to evaluate the interaction of photodynamic therapy (PDT) and intravesical drugs (thiotepa, adriamycin, mitomycin C and BCG) in a murine transitional cell carcinoma (MBT-2) model. C3H/He mice with implanted MBT-2 flank tumors were treated with either thiotepa (TT), adriamycin (ADM), mitomycin C, Bacillus Calmette-Guerin (BCG), photodynamic therapy (PDT) or a combination of the drug and PDT. The MBT-2 tumor showed sensitivity to adriamycin, MMC or PDT compared to control. PDT combined with either adriamycin, MMC or BCG, produced a greater retardation in the growth of the MBT-2 tumor than monotherapy with adriamycin, MMC, BCG or PDT. PDT combined with the anticancer agents currently used in intravesical therapy for bladder cancer is well tolerated. The combination of PDT and intravesical drugs may enhance the tumoricidal effect of either treatment used alone.

Management of stage A prostate cancer

Transrectal ultrasonography has defined a new category of stage A disease, namely nonpalpable lesions diagnosed by needle biopsy. How this type relates to classic stage A disease is unclear. Stage A1 carcinoma becomes clinically significant only in a distinct minority of patients, and even in this group, progression does not necessarily mean significant morbidity or death from prostate cancer. An aggressive approach is not justified. In contrast, stage A2 cancer is usually virulent, and aggressive therapy with curative intent is justified in patients of appropriate age and health. Both radical prostatectomy and external irradiation appear to provide long-term survival rates superior to those obtained with observation alone, but nearly 20% of these patients will die of cancer despite therapy. Unfortunately, forecasting the outcome in an individual case is still not possible, and efforts to identify prognostic features must continue. In the meantime, emotional arguments in favor of the treatment of all discovered cancers must be suppressed by an informed and objective understanding of the natural history of nonpalpable prostate cancer and the potential impact of treatment.

Red cell enzyme and serum protein polymorphisms in South Korea

Two population groups in South Korea, one from Kwangju and one from Kangreung, were studied in regard to the erythrocyte enzyme polymorphisms GPT, ACP, GLO, ESD, 6PGD, ADA, AK, PGP and subtypes of PGM1 as well as regarding the serum protein variants of C3, HP, BF, PLG, AMY and the subtypes of GC, TF and PI. The results were compared with data of the population groups from the area of Cheju Island, Taejon and Seoul. The Korean population showed a rather high degree of genetic homogeneity.

Ontogeny of cyclic AMP and cyclic GMP phosphodiesterase activities and of calmodulin levels in guinea pig ureter

Cyclic AMP and cyclic GMP phosphodiesterase (PDE) activities and calmodulin levels were determined in ureters from guinea pigs of the following ages: 50 and 56 days fetuses, three, 10, 21, 50, and 90 days, and three years old. While there is little change in ureteral cyclic AMP-PDE with age, cyclic GMP-PDE increases with age. Activity of cyclic GMP-PDE in supernatants prepared from three-year-old guinea pig ureter homogenates is 462% and 216% higher than that from 50-day fetus and three-day animals, respectively. Calmodulin levels have a bimodal distribution with age; values are highest in supernatants from 10 and 21 day ureters, but also increase in the three-year ureters when compared to 50 and 90-day values.

Age dependence of adenylate cyclase in guinea pig ureter homogenate

Adenylate cyclase activity was measured in ureteral homogenates from guinea pigs of five age groups, ranging from neonates to older adults (retired breeders). Isoproterenol stimulation of adenylate cyclase activity is lost completely in ureters from 90 day and older animals. Forskolin activation also declines rapidly with increasing age; there is a significant (39%) decrease in activation at 30 days when compared to 10-day values with a further decline at 90 days. At 90 days, NaF, GTP and 5'-guanylimido-diphosphate stimulation of adenylate cyclase decreases by only 1, 9 and 23%, respectively, from the 10-day values. Prostaglandin E1 stimulation over 5'-guanylimido-diphosphate control does not decrease with age. 5'-Guanylimido-diphosphate in the presence of ethanol, activates adenylate cyclase to a greater extent in the older animals. These data may suggest that the decreased ability to activate adenylate cyclase with age may be due to a loss of the efficiency of coupling in the more rigid aged membranes. Other explanations include loss of catalytic function with age. The loss of adenylate cyclase activity in aging correlates well with our previously reported study showing that isoproterenol causes a greater decrease in contractility of ureters from younger than from older guinea pigs.