Circulating immune complexes during immunotherapy.

Chronic immunization may lead to the production of circulating immune complexes (CICs). This study was undertaken to determine the presence of circulating IgG immune complexes in 95 subjects with allergic rhinitis/asthma receiving immunotherapy, 46 individuals with similar diagnosis but not on immunotherapy, and 64 healthy controls. Modified Raji cell and murine leukemia cell (L-1210) assays, selected for a high density of Fc receptors and devoid of Epstein-Barr virus membrane antigen, were used. Other immunological parameters such as immunologlobulins G, A, M, E, and rheumatoid factor activity were also studied. The CIC concentrations in the treated group did not differ significantly from the untreated group, although both groups did have a significantly higher concentration than the healthy controls. The presence of CICs has no relationship with age or sex of patients, dosage of allergen administered, number and nature of allergens received, period between the time of last injection and the blood sampling, and the duration of immunotherapy. Serum IgG, IgA, IgM, and rheumatoid factor activity did not differ between the treated and untreated groups. IgE was significantly higher in the treated group when compared with the untreated, and IgE levels in treated patients with elevated CICs were significantly increased compared with CIC-negative treated patients. These data suggest that CICs are present in serum of atopic diseases such as allergic rhinitis/asthma. Significantly, an association of elevation of CICs with immunotherapy could not be demonstrated.     

Apolipoprotein D is down-regulated during malignant transformation of neurofibromas

Apolipoprotein D (apoD) expression was studied in nonneoplastic peripheral nerve, neurofibromas (NFs), and malignant peripheral nerve sheath tumors (MPNSTs) by quantitative polymerase chain reaction, in situ hybridization, and immunohistochemistry. Multiplex quantitative polymerase chain reaction for messenger RNA was performed on a series of formalin-fixed and paraffin-embedded specimens that included 9 MPNSTs, 12 NFs, and 4 normal peripheral nerves. The average apoD expression was 108-fold decreased (DeltaCt = -7.3) in the MPNSTs compared with the NFs (P < .05). ApoD expression levels were 3.0-fold elevated (DeltaCt = 1.7) in the NFs compared with nonneoplastic peripheral nerve (P < .05). In situ hybridization for apoD RNA was performed on a separate series of 10 cases in which each microscopic section included both MPNST and the NF from which it arose. These studies confirmed elevated apoD expression in NFs compared with MPNSTs and demonstrated that this expression was variable among individual cells within the NFs. Differential expression by immunohistochemistry could only be demonstrated in selected areas, most likely because apoD protein is a small molecule that is secreted out of the cell into the extracellular space and plasma. ApoD expression initially increases a small amount with the formation of NFs from nonneoplastic peripheral nerve and subsequently decreases markedly as NFs transform into MPNSTs. This expression pattern may serve as a marker for cell cycle inhibition during peripheral nerve tumorigenesis.     

Influence of disodium ethane-1-hydroxy-1,1-diphosphonate on vitamin D metabolism in rats

Summary The metabolism and the organ distribution of double labelled vitamin D₃ (1,2-³H-4-¹⁴C-cholecalciferol) has been studied in rats in which the bone mineralization and the intestinal calcium absorption have been inhibited by a large pose (10 mg P/kg s.c. for 7–14 days) of disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP). The most striking difference found was a reduced accumulation of radioactive cholecalciferol and its metabolites in the kidney of EHDP-treated rats. It is unlikely that this effect was due to an unspecific alteration of the functional renal tissue since blood urea, glomerular filtration rate and renal plasm a flow remained unaltered by this dose of EHDP. The EHDP-treated rats were able to form the metabolite eluted with peak IV of the silicic acid chromatographic system, that is 25-hydroxycholecalciferol. In these vitamin D repleted rats fed a high calcium diet, the tritium deficient metabolite eluted with peak V (1,25-dihydroxycholecalciferol) was only found in the intestinal mucosa of both control and EHDP groups three days after the injection of radioactive cholecalciferol, and this in a very small amount. Therefore no definitive conclusion can be drawn as to a possible interference of EHDP treatment on the production of 1,25-dihydroxycholecalciferol. The change in the renal metabolism of vitamin D in rats treated with a rachitogenic dose of EHDP may be caused by the modifications of the calcium metabolism brought about by the diphosphonate. Its relation, if any, with the decreased calcium absorption remains to be established.     

Renal glomerulogenesis in medaka fish, Oryzias latipes

We provide an overview of glomerulogenesis in medaka from the embryo to the adult by means of in situ hybridization with the wt1 gene as a marker as well as histology and three-dimensional images. The pronephric glomus starts to develop in the intermediate mesoderm during early somitogenesis, is completed before hatching, and persists throughout the lifetime of the fish. Within 5 days after hatching, mesonephric glomerulus formation begins in the caudomedial end of the pronephric sinus and duct area. The number of glomeruli reaches approximately 200-300 in each kidney within 2 months after hatching. wt1 expression during nephron maturation served as a marker for the formation of the mesenchymal condensate and the nephrogenic body. Existence of mesenchymal condensates and persistence of wt1 expression in the adult kidney suggest that the mesonephros retains precursor cells that may be capable of contributing to neoglomerulogenesis during adulthood. Developmental Dynamics 237:2342-2352, 2008. (c) 2008 Wiley-Liss, Inc.     

Molecular analysis of streptogramin resistance in enterococci

The new semi-synthetic streptogramin antibiotic combination quinupristin/dalfopristin (Synercid) is a promising alternative for a treatment of infections with multiple resistant gram-positive pathogens, e.g. glycopeptide- and multi-resistant Enterococcus faecium. Streptogramins consist of two unrelated compounds, a streptogramin A and B, which act synergistically when given in combination. Mechanisms conferring resistance against both components are essential for resistance against the combination in E. faecium. In this species resistance to streptogramin A compounds is mediated via related acetyltransferases VatD and VatE. Resistance against streptogramins B is either encoded by the widespread ermB gene cluster conferring resistance to macrolide-lincosamide-streptogramin B antibiotics or via expression of the vgbA gene, which encodes a staphylococcal-type lactonase. E. faecalis is intrinsically resistant to streptogramins. Due to a wide use of streptogramins (virginiamycins S/M) in commercial animal farming a reservoir of streptogramin-resistant E. faecium isolates had already been selected. Determinants for streptogramin resistance are localized on plasmids that can be transferred into an E. faecium recipient both in vitro in filter-matings and in vivo in the digestive tracts of rats. Hybridization and sequencing experiments revealed a linkage of resistance determinants for streptogramins A and B on definite plasmid fragments.     

维生素D3受体对hsp90β基因表达的调控作用

鉴于热休克蛋白９０β（ｈｓｐ９０β）基因内含子中含有维生素Ｄ３受体（ＶＤＲ）结合位点，为探讨作为核受体家族成员的ＶＤＲ是否对核受体特异分子伴侣的ｈｓｐ９０β基因的表达具有调控作用，我们开展了本项研究。分别将野生型ＶＤＲ、含Ｎ端（１～１３３氨基酸残基）及Ｃ端（２８１～４２７氨基酸残基）片段的ＶＤＲ突变体真核表达质粒与人ｈｓｐ９０β基因调控片段（－１０３９／＋１５３１）介导的氯霉素乙酰基转移酶（ＣＡＴ）报告基因质粒共转染Ｊｕｒｋａｔ细胞，检测正常及经热休克（４２℃，１ｈ）处理后细胞裂解液中ＣＡＴ活性。结果表明ＶＤＲＮ端增强、而Ｃ端抑制ｈｓｐ９０β的组成性表达；在热诱导条件下野生型ＶＤＲ对ｈｓｐ９０β的表达有一定的抑制作用，而其Ｃ端片段的抑制较强。为进一步研究ＶＤＲ对细胞内源性热休克基因表达的影响，我们用ＲＴＰＣＲ方法研究了ＶＤＲ的对细胞内ｈｓｐ９０β基因ｍＲＮＡ水平的影响，发现ＶＤＲ过表达对ｈｓｐ９０β的热诱导表达明显抑制。结果提示ＶＤＲ对ｈｓｐ９０β基因的组成性和热诱导表达的调控机制不同。     

Immunohistochemical analysis of thymidylate synthase, p16(INK4a), cyclin-dependent kinase 4 and cyclin D1 in colorectal cancers receiving preoperative chemotherapy: significance of p16(INK4a)-mediated cellular arrest as an indicator of chemosensitivity to 5-fluorouracil

High expression of thymidylate synthase (TS) is allegedly associated with the chemoresistance to 5-fluorouracil (5-FU) in colorectal cancers. However, low TS expression does not necessarily imply chemosensitivity. Inactivation of p16(INK4a) correlates with poor prognosis in various cancers. We immunohistochemically evaluated the relationship between the expression of TS, p16(INK4a), CDK4 and cyclin D1 and the effect of 5-FU-based chemotherapy in colorectal cancers. After antigen retrieval, immunoperoxidase staining was performed on the paraffin-embedded, biopsy and surgical specimens of 37 advanced colorectal cancers preoperatively treated with peroral administration of 5-FU derivatives. As a control group, 31 colorectal cancers without preoperative treatment were analyzed. High TS expression was found in 23 (74%) of 31 tumors resected from histological non-responders and in 19 (61%) of 31 controls but in none of six responders. High p16(INK4a) expression was seen in 83% of the responders, 52% of the non-responders and 32% of the controls. The TS-low/p16(INK4a)-high phenotype was noted in 83% of the responders, but only in 3% of the non-responders (P = 0.0001). Induction of p16(INK4a) expression after chemotherapy was predominantly seen in the responders. Neither CDK4 nor cyclin D1 expression was related to the chemotherapeutic effects. In conclusion, the combination of low expression of TS and induction of p16(INK4a) after chemotherapy can be important indicators of the sensitivity to 5-FU-based chemotherapy in colorectal cancers.     

Multi-center, double-blind, placebo-controlled trial of fluocortin butyl in perennial rhinitis

Fluocortin butyl (FCB) is a newly synthesized corticosteroid with a high ratio of topical to systemic activity. FCB was studied in a multi-center, double-blind, placebo-controlled trial of therapy of perennial rhinitis. The study was conducted between January and May 1981. Patients evaluated suffered from either chronic allergic or chronic nonallergic rhinitis or both. A total of 306 patients from 16 investigative centers were evaluated by comparing FCB to placebo. Three separate dosage regimens were employed. Patients received a total daily dose of 2, 4, or 8 mg. FCB was found to be an effective therapeutic agent. It reduced symptoms of nasal congestion, rhinorrhea, postnasal drainage, and sneezing. It also markedly reduced the use of concomitant medications (chlorpheniramine maleate and/or pseudoephedrine). Relief of symptoms was noted as early as the first week of therapy, and the degree of improvement increased progressively during the study. There was little difference between the relief produced by the 4 mg and 8 mg regimens. Both of these were superior to the 2 mg regimen. The drug was well tolerated; no significant side effects were noted.     

Morphological variability, lectin binding and Na+,K+-activated adenosine triphosphatase activity of isolated Müller (glial) cells from the rabbit retina

Rabbit retinal Müller cells were isolated by means of papaine and mechanical dissociation. These cells were shown to have a well preserved morphology and to preserve viability for many hours. Intense wheat germ agglutinin binding occurs on the photoreceptor side of Müller cells, especially in the microvillous region. Rabbit retinal Müller cells have a Na+,K+-activated adenosine triphosphatase activity in the same order of magnitude as brain astroglial cells.