Effect of PLGA hydrophilia on the drug release and the hypoglucemic activity of different insulin-loaded PLGA microspheres

The effects of viscosity and hydrophilic characteristics of different PLGA polymers on the microencapsulation of insulin have been studied in vitro and in vivo after subcutaneous administration to hyperglycemic rats. Hydrophilic PLGA polymers produced a higher burst effect than the hydrophobic ones. Moreover, an incomplete insulin release was observed with the hydrophilic PLGA polymers in comparison with the hydrophobic ones. An explanation for that incomplete release can be the development of polymer-insulin interactions associated to the polymer hydrophilic/hydrophobic character, as detected by DSC analysis. Differences in the release rate of microsphere formulations lead to differences in the hypoglycemic action and the weight of animals. Hydrophobic PLGA was able to prolong the hypoglycemic action up to 4 weeks which is at least double than that obtained with hydrophilic PLGA of a similar viscosity. Comparing insulin microspheres with an immediate release formulation, microspheres can increase insulin relative bioavailability up to four times.

Proliferation and apoptosis in aged and photoregressed mammalian seminiferous epithelium, with particular attention to rodents and humans

Imbalances in the proliferation and apoptosis processes are involved in numerous epithelial alterations. In the seminiferous epithelium, normal spermatogenesis is regulated by spermatogonia proliferation and germ cell apoptosis, and both processes are involved in diverse pathological alterations of the seminiferous epithelium. Other physiological phenomena including aging and short photoperiod, in which apoptosis and proliferation seem to play important roles, cause testicular changes. Aging is accompanied by diminished proliferation and increased apoptosis, the latter occurring in specific states of the seminiferous cycle and considered the cause of epithelium involution. However, there is no clear evidence concerning whether proliferation decreases in the spermatogonia themselves or is due to an alteration in the cell microenvironment that surrounds them. As regards the factors that regulate the process, the data are scant, but it is considered that the diminution of c-kit expression in the spermatagonia, together with the diminution in antiapoptotic factors (Bcl-x(L))) of the intrinsic molecular pathway of apoptosis play a part in epithelial regression. A short photoperiod, especially in rodents, produces a gradual involution of the seminiferous epithelium, which is related with increased apoptosis during the regression phase and a diminution of apoptosis during recrudescence. Proliferative activity varies, especially during the total regression phase, when it usually increases in the undifferentiated spermatogonia. In other species showing seasonal reproduction, however, decreased proliferation is considered the main factor in the regression of the seminiferous epithelium. Little is known about how both phenomena are regulated, although data in rodents suggest that both the intrinsic and extrinsic pathways of apoptosis contribute to the increase in this process. In conclusion, regression of the seminiferous epithelium in physiological situations, as in many pathological situations, is a result of alterations in equilibrium between the proliferation and apoptosis of germinal cell types. However, both physiological phenomena showed important differences as regard proliferation/apoptosis and their regulation pathways, probably as a result of their irreversible or reversible character.

Extended-release tacrolimus therapy in de novo kidney transplant recipients: single-center experience

BACKGROUND

Available data for extended-release tacrolimus (Tac) except in clinical trials are limited.

OBJECTIVE

To describe our initial experience with once-daily Tac in combination with corticosteroids and mycophenolate mofetil therapy in patients undergoing de novo renal transplantation.

PATIENTS AND METHODS

In this retrospective, observational, single-center study, data were obtained for 49 adult recipients treated with extended-release Tac and 30 patients treated with standard-release Tac (control group). Mean (SD) follow-up in the 2 groups was 3.5 (2.5) months and 4.0 (2.6) months, respectively. The primary characteristics were comparable between the groups.

RESULTS

The acute rejection rate in the extended-release group was 10%, and 13% in the standard-release group. Patient and graft survival rates were 98% and 96% vs 100% and 90%, respectively. Renal function in the 2 groups was comparable: serum creatinine concentration 1.3 (0.2) mg/dL vs 1.45 (0.4) mg/dL. At day 14 posttransplantation, Tac doses were 0.17 mg/kg/d vs 0.14 mg/kg/d, and blood concentrations were 9.0 ng/mL vs 14.0 ng/mL. In recipients older than 60 years, lower dosages of Tac resulted in blood concentrations similar to those in younger patients, with less variation in dosage.

CONCLUSIONS

Short-term experience with extended-release Tac therapy in de novo renal recipients confirms its efficacy and safety. Adjusting blood concentrations in the immediate posttransplantation period is less difficult with extended-release Tac compared with the twice-daily formulation.

Compative study of bladder versus enteric drainage in pancreas transplantation

INTRODUCTION

There is some controversy concerning the choice of best technique for drainage of exocrine secretions in pancreas transplantation. We compared patients with bladder drainage (BD) versus those with enteric drainage (ED).

PATIENTS AND METHODS

From March 1995 to September 2008, 118 patients (68 men and 50 women) of overall mean age of 37.8 +/- 7.8 years underwent pancreas transplantation. There were 109 simultaneous pancreas-kidney, and 9 pancreas after kidney procedures. Recipients were divided in a BD (n = 66 patients) and an ED group (n = 52).

RESULTS

Donor characteristics were similar in both groups. Thirty-two patients (48.5%) of the BD group versus none in the ED group experienced urinary tract infections (UTI; P < .001), and 16 patients (24.2%) BD versus 15 (29.4%) ED developed intraabdominal infections (P = NS). The overall rate of relaparotomies was 33.9% (n = 40): 34.8% (n = 23) in the BD versus 32.7% (n = 17) in the ED group (P = NS). Thirty patients (25.4%) lost their pancreas grafts: 21 (31.8%) in the BD group versus 9 (17.3%) in the ED group (P = .055). The acute rejection rates were 12.7%; namely, 15.2% in the BD versus 9.8% in the ED (P = NS). Three-year patient and graft survivals were equivalent in both groups: 96.1% and 65.3% in the BD versus 89.0% and 74.0% in the ED group, respectively (P = NS).

CONCLUSIONS

ED is a good alternative to BD for drainage of pancreatic graft exocrine secretions because both techniques have the same patient and graft survival, but BD is associated with a significantly higher rate of UTI and urologic complications.

188 DETECTION BY POLYMERASE CHAIN REACTION OF NEOSPORA CANINUM FROM OVUM PICKUP AND UTERINE FLUSHING FLUIDS FROM DAIRY CATTLE IN MEXICO

Neospora caninum, an intracellular protozoon, causes encephalomyelitis in dogs (Bjerkas I et al. 1984 Zentralblat fur Parasitenkunde 70, 271-274). For the past decade, neosporosis has been a main cause of abortion in dairy cattle worldwide (Anderson M et al. 2000 Anim. Reprod. Sci. 60-61, 417-431; Dubey JP 2003 Korean J. Parasitology 41, 1-16). Vertical transmission has been indicated as an important way of spreading neosporosis (Hall CA et al. 2005 Vet. Parasitology 31, 231-41); thus, we investigated whether the protozoon could be transferred by embryo production techniques. Blood samples were collected from 92 dairy cows with history of reproductive failure and abortion within the previous 90 days at 7 dairy farms in Tizayuca, Mexico. For serology evaluation, a commercial indirect ELISA kit (Civtest Bovis Neospora, Laboratories Hipra S.A, Girona, Spain), yielded 46.74% (43/92) positive results, 46.74% (43/92) negative results, and 6.52% (6/92) suspicious to N. caninum infection. Thirteen positive cows were chosen for uterine flush (UF), ovum pickup (OPU), and a blood sample collection. Lymphocytes from blood and cells within the UF and OPU collection fluids were collected after centrifugation and DNA was extracted. All samples were tested for the presence of N. caninum by PCR, using primers and protocols that amplified a 275-bp fragment of the genomic region (5-GGGTGAACCGAGGGAGTTG-3 and 5-CCTCCCAATGCGAACGAAA-3). The N. caninum vaccine (Bovilis® NeoGuard, Intervet, Santiago Tianguistenco, Mexico) was used as a positive control and water as a negative control. Uterine flush could not be obtained from 1 cow. From 13 cows seropositive to N. caninum, only 38% were positive to PCR from blood lymphocytes. In contrast, PCR amplification was obtained from OPU cell sediment in 92.31% (12/13) and in 33.33% (4/12) of UF. Of these 12 OPU- and 4 UF-positive samples, only 5 and 3 of their corresponding blood lymphocytes were positive. Our results using uterine and follicular fluid were contradictory to those published by Moskwa et al. (2008 Vet. Parasitology 158, 370-375) where oocytes and embryos were evaluated. These results indicate that N. caninum is present in the ovary and uterine lumen of the cows, suggesting a possible risk of neospora transmission during oocyte and embryo collection and transfer techniques. UNAM and UPF.

Prediction of survival by immunohistochemical stains (IHC) in stage D2 prostate cancer patients (pts): The importance of pTEN overexpression

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Background: Several signal transduction pathways,important for apoptosis and angiogenesis were idendified and their expression and correlation with survival was studied by IHC in archival prostate cancer biopsies. All pts has androgen deprivation for stage D2 disease and were followed at 3 month intervals. Methods: In an IRB approved study,42 pts had adequate tissue preserved between 1992 and 2006 and their charts were reviewed retrospectively.IHC stains to detect tumor expression of S6(ribosomal),p70s6,pTEN,AKT-1,BCL-1(Cyclin D1),VEGF,c-KIT,PDGFR-alpha and PDGFR-beta were performed by US Labs(Irvine,CA).All results were independently evaluated by two pathologists.Immunoreactivity was scored using a semiquantitative system combining intensity of staining(0–3+) and percentage of cells staining positive(0–3+).The total score was obtained by adding the scores for indensity and the percentage of positive cells,then averaging the resuts obtained by each reader.For the purpose of this study, stain intensity of 0–1+ was considered negative and the intensity of 2–3+ was considered positive.A Cox regression survival model for each stain was developed with variables known to predict survival :Gleason score,Hemoglobin(Hgb),Alkaline Phosphatase(Alk Phos),Prostate Specific Antigen(PSA),Lactate Dehydrogenase(LDH) levels. Results: The median values were: age 70yrs(56–92),Gleason score 8(6–10), LDH 171 IU/L(97–350),Hgb 12.9gm/dl (6.8–16.3), PSA 188ng/ml(2–5677),Alk Phos 139U/L(60–1756),survival 851 days(163- 6102).In univariate analysis,VEGF staining was predictive of survival (p<0.037) but not in multivariate analysis.The pTEN staining correlated with survival (p<0.0367) and a hazard ratio of 0.040 in multivariate analysis. Conclusions: In this small sample of pts, overexpression of S6,p70s6,AKT-1,BCL-1,VEGF,c-KIT,PDGFR-alpha and PDGFR-beta by IHC staining did not predict survival independently.The pTEN staining,however was strong predictor of survival in the multivariate analysis.

No significant financial relationships to disclose.

Comorbidity and survival of hepatocellular carcinoma patients at a VA medical canter

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Background: To determine whether comorbidity indices predict survival in hepatocellular carcinoma (HCC) pts. Methods: In an IRB approved protocol, we reviewed the records of pts with tissue diagnosis of HCC seen at a VA Medical Center between 1/1/1999 to 12/31/2008. Comorbidity was assessed with four comorbidity indices, the Charlson Comorbidity Index (CMI), the Kaplan- Feinstein Index (KFI), the Cumulative Illness Rating Scale (CIRS), and VA Comorbidity Scale (VACS). Demographics, ECOG PS, stage, alpha-fetoprotein (AFP) at diagnosis, hepatitis B (HBV) and C (HCV) status, alcohol use, and iron overload were also reviewed. Cox survival regression analysis was performed. Results: There were 44 pts. All pts were men. The median (M) age at diagnosis was 60.5 years (range 35–86). The overall M survival was 230 days (4–2784). There were Stage I 12 (27%) pts, Stage II 7 (16%) pts, Stage III 14 (32%) pts, and Stage IV 11 (25%) pts. The M ECOG PS was 1.0 (0–4), stage 3 (1–4), CMI 5.75 (1–16), CIRS15 3.0 (1–5), CIRS16 6.0 (1–14), CIRS17 2.0 (0.83–5.0), CIRS18 0 (0–2), CIRS19 0 (0–1), KFI 3.0 (1–3), VACS 6.0 (2–9), and AFP 56.35 (1.1–379567). HBV was positive in 10 pts (23%), HCV 26 (59%) pts, alcohol use 37 (84%) pts, and iron overload 11 (25%) pts. In univariate survival analysis, stage (p<.038), ECOG PS (p<.001), AFP (p<.009), presence of iron overload (p<.006), and CMI (p<.019) were significant in predicting survival. However, age, HBV, HCV, alcohol use, CIRS15, CIRS16, CIRS17, CIRS18, KFI, and VACS were not significant for survival. In multivariate survival analyses that included stage and a comorbidity index, the CMI approaches significance (p<.077). Conclusions: In this sample, the CMI was a predictor for survival in pts with HCC. Further analysis in a larger sample is needed to provide a more definitive conclusion. This was supported by the New Jersey Commission for Cancer Research 09–1133-CCR-EO.

No significant financial relationships to disclose.

[The antiproteinuric effect of the blockage of the renin-angiotensin-aldosterone system (RAAS) in obese patients. Which treatment option is the most effective? ]

BACKGROUND

Obesity increases the risk of proteinuria and chronic renal insufficiency and hastens the progression of renal diseases. Increased activity of renin-angiotensin-aldosterone system and elevated levels of aldosterone are common in obese patients. No studies have compared the efficacy of the currently available antiproteinuric strategies (ACE inhibitors -ACEI-, angiotensin receptor blockers -ARB-, aldosterone antagonists) in obese patients with proteinuric renal diseases.

METHODS

Single centre, prospective, randomized study. Twelve obese patients (body mass index > 30 Kg/m2) with proteinuria > 0.5 g/24 h were selected from our outpatient renal clinic. Patients were consecutively treated during 6 weeks with an ACEI (lisinopril 20 mg/day), combined therapy ACEI+ARB (lisinopril 10 mg/day + candesartan 16 mg/day) and eplerenone (25 mg/day) in random order. A drug washout period of 6 weeks was established between the different treatment periods. The primary outcome point was the change in 24-h proteinuria at the end of each treatment period and the number of patients showing a proteinuria reduction greater than 25% of baseline.

RESULTS

The reduction in proteinuria induced by lisinopril (11.3+/-34.8%) was not statistically significant with respect to baseline, whereas that of lisinopril plus candesartan (26.9+/-30.6%) and eplerenone (28.4+/-31.6%) showed a statistically significant difference both with respect to baseline values and to lisinopril group. The number of patients who showed a greater than 25% proteinuria reduction was significantly higher with eplerenone (67%) and lisinopril+candesartan (67%) than with lisinopril (25%).

CONCLUSIONS

Monotherapy with an aldosterone antagonist and combination therapy with ACEI+ARB were more effective than ACEI monotherapy to reduce proteinuria in obese patients with proteinuric renal diseases.