Advantages of decellularized bovine pericardial scaffolds compared to glutaraldehyde fixed bovine pericardial patches demonstrated in a 180-day implant ovine study.

Glutaraldehyde (GA)-fixed bovine pericardial patches remain the cardiovascular industry standard despite reports of degradation, thickening, inflammation, calcification and lack of tissue remodelling. Decellularization provides the opportunity to attenuate some of these immune-mediated processes. This study compared the mechanical and morphological integrity of bovine pericardium that is GA-fixated (Glycar® patches) or decellularized (BPS), using a proprietary protocol, following implantation in an ovine model. The impact of the processing methods on tissue strength and morphology was assessed prior to implantation. Pericardial patches were then implanted in the descending aorta and main pulmonary artery of juvenile sheep (n = 6 per group) for 180 days, and clinically evaluated using echocardiography. At explanation, patches were evaluated for strength, calcification and biological interaction. Histology demonstrated a wave-like appearance of well-separated collagen fibers for BPS scaffolds that provided pore sizes adequate to promote fibroblast infiltration. The collagen of the Glycar® patches showed loss of collagen fiber integrity, making the collagen densely compacted, contributing to insignificant recipient cell infiltration. The clinical performance of both groups was excellent, and echocardiography confirmed the absence of aneurysm formation, calcification and degeneration. Explanted Glycar® patches demonstrated cells in abundance within the fibrous encapsulation that separated the implant from the host tissue. More importantly, the fibrous encapsulation also contributed to patch thickening of both the explanted aorta and pulmonary patches. The decellularized pericardial scaffolds demonstrated recellularization, resistance to calcification, re-endothelialization and adequate strength after 180-day implantation. The proprietary decellularization protocol produced pericardial scaffolds that could be considered as an alternative to GA-fixed pericardial patches.

In vitro activity of a new 'higher-lactam' antibacterial agent LY 193239.

In vitro activity of the new bicyclic pyrazolidinone LY 193239 (Eli Lilly) was evaluated against 52 clinical isolates of Haemophilus influenzae (4 were beta-lactamase producers), 32 Enterococcus faecalis, 14 Neisseria gonorrhoeae (1 beta-lactamase-positive) and 19 Neisseria meningitidis. Activity was best against Neisseria spp. and H. influenzae, including penicillinase-producing strains. Results of the time-kill study against a non-enzyme-mediated penicillin resistant strain of N. meningitidis indicate that exposure to an antibacterial concentration four times the minimal inhibitory concentration was bactericidal. E. faecalis was insensitive.

Pancytopenia secondary to primary malignant lymphoma of bone marrow as the first hematologic manifestation of the Estren-Dameshek variant of Fanconi's anemia.

We describe a 4-month-old girl with Estren-Dameshek variant of Fanconi's anemia (FA) presenting with a pancytopenia secondary to extranodal bone marrow malignant lymphoma as the first hematologic manifestation of the syndrome. Although she was phenotypically normal, her cultured lymphocytes showed an increased spontaneous chromosome breakage, which was enhanced by diepoxybutane (DEB). Cytogenetic studies showed that 7 of her 12 relatives, including both parents, were heterozygote carriers of the FA gene. This confirms the diagnosis of FA of the Estren-Dameshek variant. A complete hematologic remission was attained within 28 days, and she remained in continuous bone marrow remission till the age of 14.5 months, when she developed acute gastroenteritis and died. No unusual sensitivity to chemotherapy was experienced, though leukopenia and recurrent infections proved troublesome. FA has an incidence many times higher in the Orange Free State region of South Africa than reported elsewhere in the world.