In our previous work, we found that feeding Lactobacillus johnsonii to BioBreeding diabetes-prone (BBDP) rats decreased the incidence of diabetes development. The aim of this study was to investigate host pathways affected by L. johnsonii, with specific focus on the rate-limiting enzyme of tryptophan catabolism, indoleamine 2,3-dioxygenase (IDO). Suspensions of L. johnsonii or an equal volume of vehicle were orally administered to BBDP rats. Tissue IDO was investigated using quantitative RT-PCR and Western blot, whereas tryptophan, kynurenine, and 5-hydroxytryptamine (5-HT) concentrations were quantified by HPLC and ELISA. IDO activity was also investigated using L. johnsonii culture cell-free supernatant (CFS) with affinity-purified IDO and HT-29 intestinal epithelial cells. L. johnsonii feeding resulted in a 17% reduction in serum kynurenine compared with that in vehicle-fed controls, correlating with a 1.4-fold elevation in 5-HT levels. H₂O₂ produced by L. johnsonii abolished IDO activity in vitro, and L. johnsonii feeding resulted in a 3.9-fold increase in ileum lumen H₂O₂. L. johnsonii CFS significantly reduced IDO activity in HT-29 intestinal epithelial cells (47% reduction) compared with that in vehicle-treated controls, an effect abolished by catalase treatment. These data support the role of H₂O₂ in commensal bacteria-host interactions and highlight the influence of commensal bacteria-derived H₂O₂ on host physiology.
We assessed thyroid function for 12 months after subtotal thyroidectomy in 100 tyrotoxic patients treated with propranolol alone before and immediately after operation. The operation proved safe, with low morbidity. Suppression of the hypothalamic-pituitary-thyroid axis, present in the majority one month after operation, was evidenced by normal or low levels of serum total tri-iodothyronine and thyroxine, but absent or subnormal serum thyrotropin response to thyrotropin-releasing hormone. Eighty patients were euthyroid at 12 months. Three patterns of thyroid function were observed in this group between the first and 12th months: normal serum total tri-iodothyronine, thyroxine and thyrotropin levels at all stages (20 patients); normal serum total tri-iodothyronine and thyroxine, but raised thyrotropin levels on one or more occasions (40 patients); and temporary hypothyroidism (20 patients). Of the remaining 20 patients, permanent hypothyroidism developed in 14, and six relapsed. Postoperative thyroid function was related to the estimated weight of the thyroid remnant.
SUMMARY
The ultrastructure of the adenohypophysis of the rabbit is described preliminary to reporting changes after experimental procedures. Fixation by perfusing with gluteraldehyde enabled selected regions of the gland to be removed with accuracy. Separate descriptions of the pars distalis proper, zona tuberalis, pars tuberalis and pars intermedia are therefore included.
In the pars distalis proper four types of granular cell were recognized although their function cannot be accurately determined. For convenience, therefore, they have been designated 1, 2, 3 and 4. In addition a fifth type of cell (type 5) is described which is also present in the other areas. This cell, as well as having possible phagocytic functions, appears to be concerned in the formation of a perivascular channel.
Two types of cell are recognized in the zona tuberalis, which are similar in appearance to the 3 and 4 cells of the pars distalis, although not necessarily identical in function.
The characteristic cells of the pars tuberalis are rich in cytoplasmic RNA and contain large numbers of intracellular fibrils. It is suggested that the ribosomes are concerned in the synthesis of a sedentary protein which may take the form of the microfibrils.
The pars intermedia contains a predominant cell type with large granules of varying density. The relationship of these granules to the specific hormone is discussed.
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