Ca(II) and Yb(II) complexes featuring M(C≡C)4 structural motif: enforced proximity or genuine η2 -bonding?

Bis(carbazolide) complexes M[3,6-tBu2 -1,8-(RC≡C)2 Carb]2 (THF)n (R=SiMe3 , n=0, M=Ca, Yb; R=Ph, n=1, M=Ca, Yb; n=0, M=Yb) were synthesized through transamination reaction of M[N(SiMe3 )2 ]2 (THF)2 with two molar equivalents of carbazoles. The complexes feature M(η2 -C≡C)4 structural motif composed of M(II) ions encapsulated by four acetylene fragments due to atypical for alkaline- and rare-earth metals η2 -interactions with triple C≡C bond. This interaction is evidenced experimentally by X-ray diffraction, Raman spectroscopy in the solid state and by NMR-spectroscopy in the solution. According to QTAIM analysis there are 4 bond critical points (3;-1) between the metal atom and each of the triple bonds, which are connected by a strongly curved, almost T-shaped bond pathway.

Atypical Presentation of Pediatric Systemic Lupus Erythematosus Complicated by Cryptococcal Meningitis.

BACKGROUND: Cryptococcus is an opportunistic fungal pathogen that leads to life-threatening infections. Cryptococcal infections are mainly reported in HIV patients and less commonly encountered in non-HIV immunocompromised host. Cryptococcus neoformans (C. neoformans) is the most common Cryptococcus species causing diseases in humans which can be presented as pulmonary, meningitis, cutaneous, and/or disseminated cryptococcosis. Case Presentation. A 12-year-old female girl from Cairo, Egypt, presented to the pediatric hospital with signs of systemic lupus erythematosus (SLE). She had an aggressive lupus nephritis course for which corticosteroids, mycophenolate mofetil, and cyclophosphamide were prescribed, and the child gradually improved and was discharged. Two months later, the patient exhibited skin lesions involved both in her legs, massive ulcers were developed and extended rapidly through the entire legs followed by deterioration in her conscious level, and signs of meningitis were documented. Cerebrospinal fluid (CSF) examination and microbiological workup were confirmatory for C. neoformans infection, and mental and motor functions were rapidly deteriorated. Treatment with amphotericin B in addition to supportive treatment and close follow-up of the patient's medical condition result in obvious clinical improvement and patient discharge with minimal residual weakness in her legs after almost a one-month duration. After six months, the patient was brought to the emergency department complaining of repeated attacks of seizures, a lumbar puncture was performed, and culture results were again confirmatory for C. neoformans. An intensive course of antifungal therapy was prescribed which was successful, evident by resolution of the signs and symptoms of infection in addition to negative culture results and negative sepsis biomarkers. The child clinically improved, but unfortunately, gradual optic nerve degeneration and brain cell atrophy as a sequel of severe and longstanding cryptococcal infection resulted in her death after almost one year from her first attack. CONCLUSION: Cryptococcal infection among non-HIV patients is a rare disease but can result in advanced medical complications which may be fatal. The disease should be suspected to be reliably diagnosed. Cryptococcus infection can be presented as a skin lesion which, if not treated properly at an earlier time, can result in dissemination and life-threatening consequences. Amphotericin B can be used effectively in cryptococcosis management in the settings where flucytosine is not available. Signs of cryptococcal meningitis can be manifested again after a period of remission and clinical cure which signifies the latency of Cryptococcus in the central nervous system. The second activation of Cryptococcus after its latency is usually life-threatening and mostly fatal.

Amelioration of paracetamol hepatotoxicity and oxidative stress on mice liver with silymarin and Nigella sativa extract supplements

Objective: To evaluate the ameliorator property of silymarin or/and Nigella sativa (N. sativa) extract against N-acetyl-p-aminophenol (APAP)-induced injury in male mice at the biochemical, histological and ultrastructural levels. Methods: The mice were divided into seven groups (10/group). The first group was served as control. While, the second group was treated with dose of APAP. The third and fourth groups were treated with silymarin alone and N. sativa extract alone respectively. The fifth and sixth groups were treated with combination of APAP with silymarin and APAP with N. sativa extract respectively. The seventh group was treated with combination of both ameliorative compounds (silymarin and N. sativa extract) with APAP and all animals were treated for a period of 30 days. Results: Exposure to APAP at the treated dose to mice led to an alteration of liver functions, increased the alanine transaminase, aspartate aminotransferase and lactate dehydrogenase levels, decreased total protein level as well as increasing the superoxide dismutase and malondialdehyde while decreased catalase, glutathione peroxidase and glutathione reduced activities. The levels of APAP on the biochemical parameters of mice were dose-dependent. Administration of silymarin or/and N. sativa extract to APAPtreated mice attenuates the toxicity of this compound, objectified by biochemical, histological and ultrastructural improvement of liver. But the alleviation was more pronounced with the both antioxidants. Conclusions: The synergistic effect of silymarin and N. sativa extract is the most powerful in reducing the toxicity induced by APAP and improving the liver functions and antioxidant capacities of mice.