Identification of a host cell protein impurity in therapeutic protein, P1.

Residual host cell proteins (HCPs) are process-related impurities present in biotherapeutics that can pose safety health risks to patients. An adequate control of HCP levels in the final product, and demonstration of HCP clearance throughout a product manufacturing process is critical for all biotherapeutic products. Developing effective downstream purification processes can be challenging as HCPs and product proteins may possess an affinity for each other or have similar physicochemical properties, resulting in co-purification. In the current study, we identified the presence of CHO-catalase subunit protein as an impurity present in purified P1 protein. This previously unreported HCP impurity, was detected in P1 protein generated in Chinese hamster ovary (CHO) cells. Purified drug substance samples contained elevated CHO HCP levels when measured using a commercial anti-CHO HCP Enzyme-Linked Immunosorbent Assay (ELISA) kit. This finding, prompted further characterization of the HCP profile using 1D and 2D gels/ western blots using an anti-human IgG antibody as well as a commercial anti-CHO HCP antibody (Cygnus 813) for the detection of host cell proteins. The CHO-catalase protein has been characterized using a combination approach of one-dimensional (1D) and two-dimensional (2D) gels and western blotting techniques, and the identity confirmed using liquid chromatography-mass spectrometry (LC-MS/MS) analysis. Western blot analyses using the anti-CHO HCP antibody detected a potential HCP band at ∼60 kDa and a pI of ∼8 in the purified P1 sample. The 60 kDa HCP band was excised from 1D SDS-PAGE gels and LC-MS/MS analysis identified it to be CHO-catalase subunit. The identity of catalase monomer was further confirmed by western blot analysis using a specific anti-catalase antibody.

Effect of cost-effective substrates on growth cycle and yield of lingzhi or reishi medicinal mushroom, Ganoderma lucidum (higher Basidiomycetes) from Northwestern Himalaya (India).

To find a cost-effective alternative substrate, the medicinal mushroom Ganoderma lucidum was grown on sawdusts of sheesham, mango, and poplar. Optimum spawn level was determined by spawning in substrates at various levels (1, 2, 3, and 4%). To determine the effect of supplementation, substrates were supplemented with wheat bran, rice bran and corn flour at different concentrations (10, 20, and 30%). Duration of growth cycle, mushroom yield, and biological efficiency data were recorded. Among substrates, mango sawdust was superior, with 1.5-fold higher yields than poplar sawdust, which was the least suitable. However with respect to fructification, mango sawdust produced the first primordia earlier (21±1 days) compared with the other investigated substrates. 3% spawn level was found to be optimal irrespective of the substrate. Yield and biological efficiency (BE) were maximally enhanced by supplementation with wheat bran, whereas rice bran was the least suitable supplement among those tested. Growth cycle shortened and mushroom yield increased to a maximum at the 20% level of supplements. Mango sawdust in combination with 20% wheat bran, if spawned at the 3% level, resulted in a high yield (BE = 58.57%).

Atypical vascular lesion of the breast.

Atypical vascular lesions (AVLs) are vascular proliferations that develop after surgery and radiation for breast carcinoma and may represent precursors to angiosarcoma. AVLs are not well-known entities and currently lack official prognostic factors and guidelines for surgical treatment. We report the case of a patient who developed an AVL, vascular type, 4 years after lumpectomy and radiation therapy for ductal carcinoma in situ of the breast. The patient underwent wide local excision with 1-cm margins with subsequent pathologic examination confirming complete excision of the residual atypical vascular proliferation. This case highlights the importance of close cutaneous surveillance in patients with a history of surgery and radiation for breast carcinoma, and a low threshold for biopsy. More studies are needed to further delineate the risk of AVLs progressing to angiosarcoma and to identify histologic features or immunophenotypic markers, which may be predictive of this risk. Furthermore, formal treatment recommendations for these enigmatic entities would be helpful.

Reduction in the incidence of squamous cell carcinoma in solid organ transplant recipients treated with cyclic photodynamic therapy.

BACKGROUND AND OBJECTIVES: Squamous cell carcinomas (SCCs) produce significant morbidity in solid organ transplant recipients (SOTRs), particularly in patients who develop multiple tumors. Topical photodynamic therapy (PDT) has been shown to decrease the number of keratotic lesions in SOTRs, but the duration of the beneficial effect is limited. The aim of this study was to evaluate the potential benefit of cyclic PDT in the prevention of new SCCs in SOTRs. METHODS: Twelve high-risk SOTRs received cyclic PDT treatments at 4- to 8-week intervals for 2 years. The development of new SCCs (invasive and in situ) performed 12 and 24 months after the start of cyclic PDT were compared with the number of SCCs developed during the year before initiation of cyclic PDT. RESULTS: The median reduction in the 12- and 24-month post-treatment counts from the 1-month pretreatment counts was 79.0% (73.3-81.8%) and 95.0% (87.5-100.0%), respectively. Treatments were well tolerated. CONCLUSION: Cyclic PDT with 5-aminolevulinic acid may reduce the incidence of SCC in SOTRs. Additional studies with larger numbers of patients and optimized protocols are necessary to further explore the potential benefits of cyclic PDT in the prevention of skin cancer in this high-risk patient population.

Idiopathic eruptive macular pigmentation: a case of 21 years' duration.

Idiopathic eruptive macular pigmentation is a rare condition characterized by asymptomatic pigmented macules involving the neck, trunk, and proximal portions of the extremities. Age at onset usually varies from 1 to 20 years. The lesions usually appear abruptly and remit spontaneously over months to years. An unusual case of a 24-year-old woman with idiopathic eruptive macular pigmentation lasting 21 years was characterized by several periods of spontaneous resolution followed by recurrences.