Introductory comment

Objectives Injectable poly‐l ‐lactic acid (PLLA; Sculptra^®) is widely used throughout Europe and the USA to restore volume in depressed areas of the face by stimulating neocollagenesis. Injectable PLLA was previously marketed as New‐Fill™, which was often injected incorrectly and at too high a concentration, resulting in some physicians losing confidence in this product. Today, Sculptra^® is still regarded with a degree of scepticism by some physicians, due to direct or indirect experience with New‐Fill. Sculptra^®, both in formulation and use, is vastly superior to New‐Fill and clinical experience with this product dispels the myths associated with the earlier types of injectable PLLA. Results PLLA is a very safe, biodegradable compound that has been used in a wide range of medical devices for the last 30 years. In injectable form a good safety profile has been proven; however, when the device is overconcentrated, localized overstimulation of the fibroblasts can result in the formation of small lumps (subcutaneous papules), which are non‐pathological but nevertheless palpable by the patient. Physicians must also be trained in the injection of this device, as incorrect injection technique can cause device‐related adverse events. Conclusion New product guidelines have ensured that problems with PLLA concentration have been countered, and tried and tested injection techniques have been shown to ameliorate device‐related adverse events, both of which are dispelling the myths associated with modern injectable PLLA.     

A Phase II Study of Capecitabine, Oxaliplatin, and Cetuximab with or Without Bevacizumab as Frontline Therapy for Metastatic Colorectal Cancer. A Fox Chase Extramural Research Study

Objectives

Dual inhibition of vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) demonstrated initial promise in clinical trials. This phase II study tested the efficacy and safety of capecitabine, oxaliplatin, and cetuximab with or without bevacizumab as first-line treatment for metastatic colorectal cancer patients.

Methods

Patients were randomized to receive capecitabine 850 mg/m² PO twice daily for 14 days, oxaliplatin 130 mg/m² IV day 1, and cetuximab 400 mg/m² IV loading dose followed by 250 mg/m² IV days 1, 8, and 15 with (Arm A) or without (Arm B) bevacizumab 7.5 mg/kg IV day 1 every 21 days. Tumor samples were collected and retrospectively analyzed for KRAS mutation status. The primary endpoint was response rate, with time to progression (TTP) and overall survival (OS) as secondary objectives.

Results

Twenty-three patients (12 in Arm A, 11 in Arm B) were enrolled onto the study. Median follow-up was 25.9 months. Both treatments were well tolerated, with expected higher rates of grade 1/2 hypertension and bleeding in Arm A. The overall response rate was 54% (36.4% in Arm A and 72.7% in Arm B). Median time to progression was 8.7 months in Arm A and 14.4 months in Arm B. The median survival was 18.0 months in Arm A and 42.5 months in Arm B. The study was prematurely terminated after other studies reported inferior outcomes with dual antibody therapy.

Conclusions

Although terminated early, the study supports the detrimental effect of combining VEGF and EGFR inhibition in metastatic colorectal cancer.     

The distribution of porcine pancreatic beta-cells at ages 5, 12 and 24 weeks

Jay TR, Heald KA, Carless NJ, Topham DE, Downing R. The distribution of porcine pancreatic beta-cells at ages 5, 12 and 24 weeks. Xenotransplantation 1999; 6: 131-140. ©Munksgaard, Copenhagen Islet transplantation is a potential treatment for diabetes mellitus and porcine pancreata may provide a readily available source of islets. The size, number and distribution of islets within the pancreas may influence the choice of age of donor for xenotransplantation. Samples (n = 3 per age group) from the dorsal and ventral pancreas of 5-, 12- and 24-week-old hybrid pigs were fixed in formal saline, processed in paraffin wax and stained with an avidin/biotin immunohistochemical kit for insulin, glucagon, somatostatin and pancreatic polypeptide. The arrangement of endocrine cells within the pancreata were studied and mean diameter of β-cell groups were measured (from insulin stained sections) in 1 mm² grid areas (n = 10 per section) and collated into groups according to size. Percentage volume density of β-cells in relation to the whole pancreas was calculated and also the distribution of β-cell groups, according to their size, within the total β-cell mass. There were differences in the frequency and arrangement of endocrine cells within islets at the different ages studied. β-Cell groups < 50 µm in diameter occupied 70 to 80% of the total β-cell mass at 5 weeks but, as the age of the pig increased, larger cell groups were more abundant. However, the percentage volume density of β-cells within the total pancreas did not change as the pancreas matured.This study shows that the endocrine porcine pancreas was maturing and its structure changed between the ages of 5 and 24 weeks. The relevance of these findings may have implications on the isolation and function of islets if young pigs are to be used as donors for transplantation as a treatment for diabetes mellitus.     

Combined 1-Deoxynojirimycin and Ibuprofen Treatment Decreases Microglial Activation,Phagocytosis and Dopaminergic Degeneration in MPTP-Treated Mice

Inflammation is a predominant aspect of neurodegenerative diseases and experimental studies performed in animal models of Parkinson’s disease (PD) suggesting that a sustained neuroinflammation exacerbates the nigrostriatal degeneration pathway. The central role of microglia in neuroinflammation has been studied as a target for potential neuroprotective drugs for PD, for example nonsteroidal anti-inflammatory drugs (NSAIDs) and matrix metalloproteinases (MMP) inhibitors that regulates microglial activation and migration. The aim of this study was to investigate the neuroprotective response of the iminosugar 1-deoxynojirimycin (1-DNJ) and compare its effect with a combined treatment with ibuprofen. MPTP-treated mice were orally dosed with ibuprofen and/or 1-DNJ 1. Open-field test was used to evaluate behavioral changes. Immunohistochemistry for dopaminergic neurons marker (TH⁺) and microglia markers (Iba-1⁺; CD68⁺) were used to investigate neuronal integrity and microglial activation in the substantia nigra pars compacta (SNpc). The pro-inflammatory cytokines TNF-α and IL-6 were analysed by qPCR. Treatments with either 1-DNJ or Ibuprofen alone did not reduce the damage induced by MPTP intoxication. However, combined treatment with 1-DNJ and ibuprofen prevents loss of mesencephalic dopaminergic neurons, decreases the number of CD68⁺/ Iba-1⁺ cells, the microglia/neurons interactions, and the pro-inflammatory cytokines, and improves behavioral changes when compared with MPTP-treated animals. In conclusion, these data demonstrate that the combined treatment with a MMPs inhibitor (1-DNJ) plus an anti-inflammatory drug (ibuprofen) has neuroprotective effects open for future therapeutic interventions.

MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) is a protoxicant that, after crossing the Blood Brain Barrier, is metabolized by astrocytic MAO-B to MPDP+, a pyridinium intermediate, which undergoes further two-electron oxidation to yield the toxic metabolite MPP+ (methyl-phenyltetrahydropyridinium) that is then selectively transported into nigral neurons via the mesencephalic dopamine transporter. In this study, we demonstrated that MPTP induced death of dopaminergic neurons, microgliosis, increase of gliapses, motor impairment and neuroinflammation in mice, which were inhibited by combined 1-deoxynojirimycin and ibuprofen treatment.

     

Preoperative chemoradiation in the management of adenocarcinoma of the body of the pancreas

Adenocarcinoma of the body of the pancreas has been traditionally associated with low resectability and poor prognosis. We reviewed 30 consecutive cases of pancreatic body adenocarcinoma presenting between 1988 and 2001. Twenty-six (87%) patients received preoperative chemotherapy (either 5-fluorouracil with or without mitomycin C or gemcitabine) plus radiation therapy (50.4 Gy), and four patients received chemoradiation postoperatively. During or shortly after chemoradiation 16 (53%) patients developed distant metastasis (n = 12), tumor progression (n = 2), or fatal septic complications (n = 2). Fourteen patients underwent surgical resection with curative intent. Resections performed included distal subtotal pancreatectomies (n = 6), extended pancreaticoduodenectomies (n = 6), and total pancreatectomies (n = 2). Ten patients (71%) required vascular reconstruction as a result of involvement of the portal vein or the superior mesenteric, hepatic arterial, or celiac vessels. Median overall survival was 34 months (range 8-152) for the resected group as compared with 8 months (range 1-14) in the unresected group (P = 0.005). Five-year actuarial overall survival is projected at 45 per cent for the resected group. In this poor-prognostic subset of patients with pancreatic cancer preoperative chemoradiation followed by an aggressive surgical approach was associated with resectability and long-term survival of a significant minority of patients.     

The cofactor role of protein S in the acceleration of whole blood clot lysis by activated protein C in vitro

The effect of purified human activated protein C (APC) and protein S on fibrinolysis was studied by using an in vitro blood clot lysis technique. Blood clots were formed from citrated blood (supplemented with 125I-fibrinogen) by adding thrombin and Ca2+-ions; lysis of the clots was achieved by adding tissue-type plasminogen activator. The release of labeled fibrin degradation products from the clots into the supernatant was followed in time. We clearly demonstrated that APC accelerates whole blood clot lysis in vitro. The effect of APC was completely quenched by antiprotein C IgG, pretreatment of APC with diisopropylfluorophosphate, and preincubation of the blood with antiprotein S IgG. This demonstrates that both the active site of APC and the presence of the cofactor, protein S, are essential for the expression of the profibrinolytic properties. At present, the substrate of APC involved in the regulation of fibrinolysis is not yet known. Analysis of the radiolabeled fibrin degradation products demonstrated that APC had no effect on the fibrin cross-linking capacity of factor XIII.