Diagnosis of Encephalitozoon cuniculi infection by western blot and the use of cross-reactive antigens for the possible detection of microsporidiosis in humans.

Microsporidia are very primitive, eukaryotic, obligate, intracellular, protozoan parasites. Encephalitozoon cuniculi, a microsporidian originally described from a rabbit infection, has been described in humans as well as in many species of laboratory animals. We report the detection of E. cuniculi by Western blotting in a rabbit with torticollis that was obtained from an Encephalitozoon-free colony. Cross-reactivity of this serum was observed with antigens prepared from several genera of microsporidia. Identical Western blotting patterns were obtained with sera obtained from a rabbit immunized with E. cuniculi that was purified from tissue culture cells. In addition, we were able to demonstrate cross-reactivity between E. cuniculi rabbit antisera and Enterocytozoon bieneusi antigens by indirect immunofluorescent assay techniques in human intestinal biopsy samples. These cross-reactions between microsporidia may be useful in developing diagnostic tests for non-cultivatable microsporidia such as Enterocytozoon bieneusi.

MRI anatomy of the rat kidney at 1.5 T in different states of hydration.

The objective of this study was to determine correlation between structural anatomy and surface coil spin-echo MR imaging of the rat kidney and the effect of hydration state on MR signal intensities of the cortex and medulla. Twelve rats were studied in a pilot study with a 3-inch surface coil in a 1.5 T magnet under five different states of hydration. Serum and urine osmolality measurements were obtained immediately prior to each scan. Signal intensity measurements were made from both T1- and T2-weighted images of the cortex and medulla of both kidneys in each state of hydration. Gross and histological anatomy of the rat kidneys was correlated with the MR images. Four distinct layers were detected in vivo on MRI images of the rat kidney; these correlated with the histological layers. T1-weighted cortico-medullary differentiation was most pronounced at 48 h dehydration; T2 cortico-medullary differentiation was greatest at 72 h of dehydration. We concluded that different parts of the mammalian nephron can be identified by MR imaging and that cortico-medullary differentiation is affected by the hydration state of the animal.

Comparison of autologous fat transfer in fresh, refrigerated, and frozen specimens: an animal model.

The rising popularity of autologous fat transfer (AFT) has raised the questions whether cryopreserved adipocytes are a suitable substrate for soft-tissue augmentation, and which storage techniques may be most suitable for a maximally successful surgical result. An animal model of AFT was conceived using isogeneic Sprague-Dawley rats. Suction harvesting of fat and subcutaneous implantation was performed with specimens stored at -16 degrees C or 1 degrees C for a period of 1 or 2 weeks, as well as a group that underwent immediate implantation. A histological comparison of the experimental and control groups clearly demonstrated a decrease in viable adipocytes and an increase in signs of inflammation and fat cell necrosis in those animals that received stored fat instead of immediate fat implantation. These changes became more severe with increased length of storage and the use of refrigeration over freezing. The authors conclude that the practice of storing harvested adipocytes for later injection is not supported by the experimental evidence and should be avoided.