Variability in 4-hydroperoxycyclophosphamide activity during clinical purging for autologous bone marrow transplantation

We examined the effects of varying incubation conditions on the in vitro activity of 4-hydroperoxycyclophosphamide (4HC). 4HC activity against CFU-GM and against the K562 tumor cell line decreased with increasing the RBC concentration of the incubation mixture. Increasing the concentration of nucleated bone marrow cells in the incubation mixture also decreased the 4HC activity. Evaluation of 53 consecutive patients undergoing autologous bone marrow transplantation (BMT) revealed that the incubation RBC concentration during clinical purging showed a similar effect on CFU-GM recovery. Aldehyde dehydrogenase content of RBCs and nucleated marrow cells appears to be the cause of the inhibition of 4HC activity. Although there was no difference in individual CFU-GM sensitivity to 4HC among normals, previously treated patients undergoing autologous BMT showed significant variability in CFU-GM sensitivity to 4HC. The combined effects of incubation RBC concentration and individual patient 4HC sensitivity appear to account for most of the variability in CFU-GM recovery and speed of hematologic recovery after clinical purging with 4HC.     

Efficacy of ex vivo purging for autologous bone marrow transplantation in the treatment of acute nonlymphoblastic leukemia

We used an in vitro measure of drug activity to predict the efficacy of ex vivo purging of leukemic cells from autologous bone marrow grafts. We previously found that the myeloid progenitor cell (CFU-GM) content of the marrow grafts after ex vivo purging with 4- hydroperoxycyclophosphamide (4-HC) correlates with time to hematologic recovery after autologous bone marrow transplantation in patients with acute nonlymphoblastic leukemia. We observed that variable red blood cell concentration of the bone marrow incubation mixture results in differential cytotoxic activity of 4-HC. The CFU-GM content of the graft after the ex vivo treatment is a measure of this 4-HC activity. We analyzed the disease-free survival of 45 patients with acute nonlymphoblastic leukemia undergoing autologous bone marrow transplantation with 4-HC purged grafts. Patients who relapsed after transplantation had 4.2 +/- 1.1% of graft CFU-GM surviving the ex vivo purge, compared with 1.1 +/- 0.4% for patients who achieved a sustained remission (P = .06). Twenty-three patients with a CFU-GM content after 4-HC purging of greater than 1% of the pretreatment value had an actuarial disease-free survival of 12%, compared to 36% for 22 patients with a less than or equal to 1% CFU-GM content after purging (P = .006). Therefore, percent CFU-GM survival as a measure of 4-HC cytotoxicity identified a group of patients with insufficient purging. Although no randomized clinical trials have documented the need for ex vivo purging, our results suggest that effective bone marrow purging is important for the optimal application of autologous transplantation in the treatment of acute nonlymphoblastic leukemia.     

Role of malaria induced oxidative stress on anaemia in pregnancy

ObjectiveTo assess the role of oxidative stress on anaemia in pregnancy.MethodsBlood samples were collected from pregnant and non-pregnant women who came for antenatal clinic and medical check at Comprehensive Health Center, Akungba-Akoko and Iwaro General Hospital in Akoko Area of Ondo State, Nigeria. Thick and thin blood films were prepared and used for malaria parasite counts. Haemoglobin level was determined by colorimetric method using Drabkin's solution. Oxidative status was determined using malondiadelhyde level as an indicator of lipid peroxidation, while ascorbic acid and reduced glutathione levels were measured by standard spectrophotometric methods.ResultsMean parasite density was significantly higher in pregnant women than non-pregnant women (P<0.05). Haemoglobin level was significantly reduced in malaria positive pregnant and non-pregnant women than malaria negative (8.3-10.0 g/dL) (P<0.05). The oxidative status indicated that malondialdehyde (MDA) was significantly increased in pregnant [(2.5±0.7) nmol/mL] than non-pregnant women [(1.8±0.1) nmol/mL] (P<0.05), while Vit C and superoxide dismutase (SOD) levels were significantly reduced in pregnant than non-pregnant women(P<0.05). There was an inverse correlation between Hb and MDA levels in pregnant women studied. Positive correlation was observed between the mean MDA level and parasite density (r = 0.53). The Hb level decreased as the parasite density and MDA level increased in pregnant women.ConclusionsThis study shows that oxidative stress, caused by malaria infection could be part of the contributing factors responsible for anaemia in pregnancy.     

Investigation of the mechanisms underlying the gastroprotective effect of nicorandil

AIM: This study investigated possible mechanisms underlying the gastroprotective effect of nicorandil on experimentally-induced gastric lesions in rats. METHODS: Rats were randomly assigned to vehicle-, nicorandil (10 mg/kg)-, glibenclamide (6 mg/kg)-, nicorandil + glibenclamide- and cimetidine-pretreated groups, in addition to non-stressed control group, to demonstrate whether the K(ATP )channel opening contributed to nicorandil's gastroprotection. Lesions were induced by water immersion-restraint stress (WIRS) and ulcer indices were determined. Gastric juice parameters (pH, acid output, pepsin and mucin concentrations) were determined. Another set of rats was divided into control, saline-pretreated and nicorandil (10 mg/kg)-pretreated groups. Rats underwent WIRS and their stomachs were used for determination of gastric mucosal lipid peroxides, histamine, PGE(2), and total nitrites levels. RESULTS: Nicorandil displayed significant protection against gastric lesions formation, abolished by concomitant administration of glibenclamide. Nicorandil significantly reduced gastric acid and pepsin secretion, but upon coadministration with glibenclamide, these effects were blocked. Additionally, nicorandil significantly reduced gastric mucosal lipid peroxides and total nitrites, but did not affect PGE(2) and histamine levels. CONCLUSION: Results confirm a gastroprotective effect for nicorandil, the mechanism of which comprises K(ATP) channel opening, free radical scavenging, decrease of pepsin and acid secretion and prevention of the detrimental rise in nitric oxide during WIRS.     

Melatonin protects against hydrogen peroxide-induced gastric injury in rats

1. Melatonin (MT) is a pineal hormone that is also abundant in the gut and has a well known role in scavenging oxygen free radicals. The aim of the present study was to evaluate the potential protective effects of MT against H(2)O(2)-induced gastric lesions in rats. 2. An experimental model of gastric ulceration was established in rats using 15% H(2)O(2). Melatonin (12.5, 25 or 50 mg/kg, intagastrically) was administered to rats 30 min before H(2)O(2) challenge. 3. Intragastric administration of H(2)O(2) resulted in haemorrhagic lesions in the fundic area of the stomach. Furthermore, H(2)O(2) induced gastric oxidative stress, as indicated by depletion of reduced glutathione (GSH), inhibition of glutathione peroxidase (GPx) activity and elevation of malonedialdehyde (MDA) levels. These effects were accompanied by decreased gastric tissue levels of prostaglandin (PG) E(2) and nitric oxide (NO), as well as increased levels of tumour necrosis factor (TNF)-alpha. Administration of MT (12.5, 25 or 50 mg/kg) 30 min before H(2)O(2) significantly attenuated the development of gastric lesions in a dose-dependent manner. The protective effects of MT were accompanied by significant inhibition of the H(2)O(2)-induced reduction in gastric content of GSH and GPx activity and elevation in MDA levels. Furthermore, MT antagonized H(2)O(2)-induced reduction of gastric PGE(2) and NO levels and elevation of TNF-alpha. 4. In conclusion, MT protects rat gastric mucosa against H(2)O(2)-induced damage. The observed protective effects of MT can be attributed, at least in part, to its anti-oxidant properties, preservation of PGE(2) and NO levels, as well as inhibition of TNF-alpha induction in gastric tissues.     

Flt3 ligand delivered in a pluronic formulation prolongs the survival of mice with orthotopic pancreatic adenocarcinoma

Pancreatic adenocarcinoma is a devastating disease, characterized by asymptomatic development and extremely poor prognosis. Given the resistance of pancreatic cancer to standard chemo- and radiotherapy, we have focused on the development of immunotherapies for this disease. The number of dendritic cells (DCs), natural killer (NK) cells, and T-cells in the blood and secondary lymphoid organs is regulated by a group of hematopoietic growth factors, which includes fms-like tyrosine kinase-3 ligand (Flt3L). We have demonstrated previously that the bioavailability and in vivo half-life of Flt3L are increased by Flt3L formulation in the pluronic ProGelzx. In this study, we first examined the effectiveness of Flt3L delivered in ProGelz against subcutaneous (s.c.) pancreatic adenocarcinomas in mice. We found that an intramuscular (i.m.) injection of Flt3L in ProGelz significantly increased the survival of mice bearing s.c. pancreatic tumors, compared to the administration of phosphate-buffered saline (PBS) in ProGelz. We then tested Flt3L in ProGelz in an orthotopic pancreatic tumor model, and demonstrated that it significantly enhanced the survival of tumor-bearing mice, compared to PBS in ProGelz. Overall, these observations suggest that Flt3L formulated in ProGelz may have potential clinical utility as a treatment for pancreatic cancer.     

Laparoscopy in the Management of Impalpable Testis: Series of 64 Cases

Background  The undescended testis represents one of the most common disorders of childhood. Laparoscopy has been widely used for the diagnosis and treatment of non-palpable testis. In this study, we investigated and evaluated the usefulness of laparoscopy in the diagnosis and treatment of the non-palpable testis. Methods  From January 2003 to January 2008, we used laparoscopy in the management of 64 patients with 75 impalpable testes. The patients’ ages varied from 1 to 15 years (median 4.6 years). The sites and sizes of the testes were localized by abdominopelvic ultrasonography (US) in all 64 children. One-stage laparoscopic orchiopexy was performed for 26 testes, staged Fowler Stephens orchiopexy for 17 testes, and laparoscopic orchidectomy for five testes. Follow-up by clinical examination and color Doppler US was performed in every patient who underwent orchiopexy. Results  There were 11 patients with bilateral non-palpable testes. The overall diagnostic agreement of US with laparoscopy was seen for only 16 of 75 testes (21.3%). The results of diagnostic laparoscopy were varied and showed various pathologic conditions and positions of the testes, such as 20 low intraabdominal testes (26.6%), 17 high intraabdominal testes (22.7%), and 18 testes (24%) that had entered the inguinal canal. Associated inguinal hernia was present in four patients. After a mean follow-up period of 26 months (6 months–5 years) all testes were seen to be located in the bottom of the scrotum, with the exception of three testes that had retracted to the neck of the scrotum and two testes that had atrophied (2.7%). Conclusions  Laparoscopy has proven to be the only diagnostic modality where the findings provide a clear, dependable direction for definitive management of impalpable testes. It allows an accurate diagnosis and simultaneous definitive treatment.